The 90% confidence interval for the population mean heart rate is [62.897, 65.103] beats per minute.
What is the 90% confidence interval for the population mean?Given:
Sample mean (x) = 64 beats per minute
Sample standard deviation (s) = 3 beats per minute
Sample size (n) = 20
Since the sample size is greater than 30 and we assume a normal distribution, we will use Z-distribution for constructing the confidence interval.
The formula for the confidence interval is: CI = x ± Z * (s / √n). The Z-score for the desired confidence level (90% confidence level corresponds to a Z-score of 1.645)
Calculating the confidence interval:
CI = 64 ± 1.645 * (3 / √20)
CI = 64 ± 1.645 * 0.671
CI ≈ 64 ± 1.103
CI ≈ [62.897, 65.103].
Read more about confidence interval
brainly.com/question/15712887
#SPJ4
give an example of a function that is k times but not k+1 times continuously differentiable.
An example of a function that is k times but not k+1 times continuously differentiable is the function f(x) = |x|^(k+1) for k ≥ 0.
Explanation:
For k ≥ 0, the function f(x) = |x|^(k+1) is k times differentiable. The derivative of f(x) is given by:
f'(x) = (k+1)|x|^k * sign(x)
where sign(x) is the signum function that returns -1 for x < 0, 0 for x = 0, and 1 for x > 0.
The second derivative of f(x) is given by:
f''(x) = k(k+1)|x|^(k-1) * sign(x)
We can see that the first derivative f'(x) exists for all values of x, including x = 0, since the signum function is defined for x = 0. However, the second derivative f''(x) is not defined at x = 0 for k ≥ 1, because the term |x|^(k-1) becomes undefined at x = 0.
Therefore, for k ≥ 1, the function f(x) = |x|^(k+1) is k times differentiable but not (k+1) times continuously differentiable at x = 0.
Note: For k = 0, the function f(x) = |x| is continuously differentiable everywhere except at x = 0.
Learn more about derivatives here: brainly.com/question/25324584
#SPJ11
(a) The Department of Education found that only 55 percent of students attend school in a remote community. If a random sample of 500 children is selected, what is the approximate probability that at least 250 children will attend school? Use normal approximation of the binomial distribution. (b) A hotel chain found that 120 out of 225 visitor who booked a room cancelled their bookings prior to the 24hr no refund period. Determine whether there is evidence that the population proportion of visitors who book their stay and cancel their bookings prior to the no refund period is less than 50% at a 1% confidence level. (c) The Queensland education department surveyed 1000 parents to assess those with having financial hardship. It was determined that 19% of the parents suffered some financial hardship of which 10% could not afford the full cost of their childs education. Construct a 99% confidence interval for the proportion of parents who are suffering financial hardhip and cannot afford the full cost of their child's education.
The approximate probability that at least 250 children will attend school in a random sample of 500 children from a remote community, based on the normal approximation of the binomial distribution, is approximately 0.987.
To solve this problem, we can use the normal approximation to the binomial distribution. The binomial distribution describes the probability of obtaining a certain number of successes (students attending school) in a fixed number of independent Bernoulli trials (each student attending school or not). In this case, the probability of a student attending school is 0.55, and the number of trials is 500.
To apply the normal approximation, we need to calculate the mean (μ) and the standard deviation (σ) of the binomial distribution. The mean is given by μ = n * p, where n is the number of trials and p is the probability of success. In this case, μ = 500 * 0.55 = 275. The standard deviation is calculated using the formula σ = sqrt(n * p * (1 - p)). Therefore, σ = sqrt(500 * 0.55 * (1 - 0.55)) ≈ 12.11.
Now, we want to find the probability that at least 250 children will attend school, which is equivalent to finding the probability of 249 or fewer children not attending school. To do this, we can use the normal distribution with mean μ and standard deviation σ, and calculate the cumulative probability up to 249. Using a standard normal table or a calculator, we find that the cumulative probability up to 249 is approximately 0.013. Therefore, the probability of at least 250 children attending school is approximately 1 - 0.013 ≈ 0.987.
Learn more about binomial distribution
brainly.com/question/29163389
#SPJ11
An accessories company finds that the cost and revenue, in dollars, of producing x belts is given by C(x)= 780 +32x-0.066x company's average profit per belt is changing when 177 belts have been produced and sold. 10 respectively. Detemine the rate at which the accessories and R(x)= 35x First, find the rate at which the average profit is changing when x belts have been produced.
The rate at which the average profit is changing when 177 belts have been produced and sold is 26.364 dollars per belt.
To find the rate at which the average profit is changing when x belts have been produced, we need to determine the derivative of the average profit function.
The average profit function is given by:
P(x) = R(x) - C(x),
where P(x) represents the average profit, R(x) represents the revenue, and C(x) represents the cost.
Given that R(x) = 35x and C(x) = 780 + 32x - 0.066x², we can substitute these values into the average profit function:
P(x) = 35x - (780 + 32x - 0.066x²).
Simplifying:
P(x) = 35x - 780 - 32x + 0.066x².
P(x) = -780 + 3x + 0.066x².
Now, let's find the derivative of P(x) with respect to x:
P'(x) = d/dx (-780 + 3x + 0.066x²).
P'(x) = 3 + 0.132x.
So, the rate at which the average profit is changing when x belts have been produced is given by P'(x) = 3 + 0.132x.
If we x = 177 into the derivative equation, we can find the rate at which the average profit is changing when 177 belts have been produced:
P'(177) = 3 + 0.132(177).
P'(177) = 3 + 23.364.
P'(177) = 26.364.
Therefore, the rate at which the average profit is changing when 177 belts have been produced and sold is 26.364 dollars per belt.
To learn more about profit click here:
brainly.com/question/32535418
#SPJ11
"HIGHLIGHTED PROBLEM IN YELLOW PLEASE!!
Problem 21 Show that the line integral is independent of path and use a potential function to evaluate the integral (a) ∫ C (z² + 2xy)dx + (x²)dy + (2xz)dz where C runs from (2,1,3) to (4,-1,0)"
(b) ∫C (2x cos z - x²) dx + (z-2y)dy + (y – x² sin z)dz where C runs from (3,-2,0) to (1,0, π)
In part (a), we are required to show that the line integral is independent of path and use a potential function to evaluate it. The line integral is given by ∫C (z² + 2xy)dx + (x²)dy + (2xz)dz, where C runs from (2,1,3) to (4,-1,0).
In part (b), we have to perform a similar analysis for the line integral ∫C (2x cos z - x²) dx + (z-2y)dy + (y – x² sin z)dz, where C runs from (3,-2,0) to (1,0, π).
(a) To show that the line integral is independent of path, we need to demonstrate that it depends only on the endpoints and not the specific path taken. We can do this by finding a potential function f(x, y, z) such that the gradient of f equals the given vector field. Calculating the partial derivatives, we find that f(x, y, z) = xz² + x²y + C, where C is a constant. To evaluate the line integral, we can use the potential function. Evaluating f at the endpoints and subtracting the values, we obtain f(4,-1,0) - f(2,1,3) = (16)(0) + (16)(-1) + C - (4)(9) - (4)(1) - (2)(27) - C = -25. Hence, the line integral is independent of path and its value is -25.
(b) Similar to part (a), we seek a potential function for the vector field. By integrating the given components, we find f(x, y, z) = x² cos z - xy + yz - x² sin z + C, where C is a constant. Using the potential function, we evaluate f at the endpoints and find f(1,0,π) - f(3,-2,0) = (1)² cos(π) - (1)(0) + (0)(π) - (1)² sin(π) + C - (3)² cos(0) - (3)(-2) + (0)(0) - (3)² sin(0) - C = 14. Hence, the line integral is independent of path and its value is 14.
The line integral in part (a) is independent of path and evaluates to -25, while the line integral in part (b) is also independent of path and its value is 14.
To learn more about line integral click here : brainly.com/question/31422009
#SPJ11
Consider a one-way classification model
$$
y_{i j}=\mu+\tau_i+\varepsilon_{i j}
$$
for $i=1,2,3$ and $j=1,2, \ldots, n_i$. The following data is collected:
\begin{tabular}{l|ccc} Factor level: & $\mathrm{A}$ & $\mathrm{B}$ & $\mathrm{C}$ \\
\hline$n_i$ & 12 & 8 & 16 \\
Mean response: & 11.3 & 8.4 & 10.2
\end{tabular}
We are also given $s^2=4.9$.
For this question, you may not use the $1 \mathrm{~m}$ function in $\mathrm{R}$.
(a) Calculate a $95 \%$ confidence interval for $\tau_A-\tau_B$.
(b) Calculate the $F$-test statistic for the hypothesis $\tau_A=\tau_B=\tau_C$, and state the degrees of freedom for the test.
(c) Test the hypothesis $H_0: \tau_C-\tau_B \geq 2$ against $H_1: \tau_C-\tau_B<2$ at the $5 \%$ significance level.
(d) Suppose the above data is collected through a completely randomised design with total sample size $n=36$. Does this design minimise 2 var $\left(f_A-\hat{t}_C\right)+\operatorname{var}\left(\hat{\tau}_B-\hat{t}_C\right)$ ? If not, what is the optimal allocation for $n_A, n_B$, and $n_C$ ?
a) The confidence interval for τA - τB is:
CI = (τA - τB) ± t* * SE(τA - τB)
b) the sum of squares: SSE = (11.3 - μA)² + (11.3 - μA)²
What is the confidence interval?
A confidence interval is a range of values that is likely to contain the true value of an unknown population parameter, such as the population mean or population proportion. It is based on a sample from the population and the level of confidence chosen by the researcher.
(a) To calculate the 95% confidence interval for τA - τB, we can use the formula:
CI = (τA - τB) ± t(α/2, df) * SE(τA - τB)
where t(α/2, df) is the t-score for the desired confidence level and degrees of freedom, and SE(τA - τB) is the standard error of the difference in means.
The degrees of freedom for the test can be calculated using the formula:
df = ∑(ni - 1)
Given the data:
nA = 12, nB = 8, and mean responses: μA = 11.3, μB = 8.4, μC = 10.2
We can calculate the standard error using the formula:
SE(τA - τB) = √((s²/nA) + (s²/nB))
where s² is the sample variance.
Calculating the degrees of freedom:
df = (nA - 1) + (nB - 1) = 11 + 7 = 18
Plugging in the values, we have:
SE(τA - τB) = √((4.9/12) + (4.9/8)) ≈ 1.313
The t-score for a 95% confidence interval with 18 degrees of freedom can be found using a t-table or statistical software. Let's assume the t-score is t*.
The confidence interval for τA - τB is:
CI = (τA - τB) ± t* * SE(τA - τB)
You would need to consult a t-table or use statistical software to find the t* value. The interval would be calculated by substituting the appropriate values.
(b) To calculate the F-test statistic for the hypothesis τA = τB = τC, we can use the formula:
F = (MSA / MSE)
where MSA is the mean square due to treatments and MSE is the mean square error.
The mean square due to treatments can be calculated as:
MSA = SSA / (k - 1)
where SSA is the sum of squares due to treatments and k is the number of groups (in this case, k = 3).
The mean square error can be calculated as:
MSE = SSE / (N - k)
where SSE is the sum of squares error and N is the total sample size.
To calculate the sum of squares:
SSA = ∑(ni * (μi - μ)²)
SSE = ∑∑((yij - μi)²)
Given the data, we can calculate the sum of squares:
SSA = (12 * (11.3 - ((11.3 + 8.4 + 10.2) / 3))^2) + (8 * (8.4 - ((11.3 + 8.4 + 10.2) / 3))²) + (16 * (10.2 - ((11.3 + 8.4 + 10.2) / 3))²)
SSE = (11.3 - μA)² + (11.3 - μA)²
Hence, a) The confidence interval for τA - τB is:
CI = (τA - τB) ± t* * SE(τA - τB)
b) the sum of squares: SSE = (11.3 - μA)² + (11.3 - μA)²
To Learn more about the confidence interval here:
https://brainly.com/question/20309162
#SPJ4
The trajectory of a particle is given by the vector function r(t) = (2+³1, -1² +t+1-21³-3t²-1) Calculate a linear approximation to the particle's trajectory at t = 2. Use the notation (x, y, z) to denote vectors. r(t) Also find the tangent to the curve at t = 2. Use the notation (x, y, z) to denote vectors, and is for the parameter. r(s) = Note: Please Do Not rescale (simplify) the direction vectors.
Linear approximation to the particle's trajectory at t = 2:r(2 + h) ≈ (3h + 8, -11h - 22, -24h - 35). Tangent to the curve at t = 2:r(s) = (3s + 8, -11s - 22, -24s - 35).
Linear approximation of r(t + h) ≈ r(t) + h * r'(t)
Here, r(t) = (2 + 3t, -1² + t + 1 - 21³ - 3t² - 1)r'(t)
= (3, 1 - 6t, -6t²)
Now, we calculate r'(2) = (3, 1 - 6(2), -6(2)²)
= (3, -11, -24)
Thus, the linear approximation to the particle's trajectory at t = 2 is given by: r(2 + h)
≈ (2 + 3(2), -1² + (2) + 1 - 21³ - 3(2)² - 1) + h(3, -11, -24)r(2 + h)
≈ (8, -22, -35) + (3h, -11h, -24h)r(2 + h)
≈ (3h + 8, -11h - 22, -24h - 35)
To find the tangent to the curve at t = 2,
we use the formula: r(s) = r(2) + s * r'(2)
Here, r(2) = (8, -22, -35)r'(2)
= (3, -11, -24)
Thus, the equation of the tangent to the curve at t = 2 is:
r(s) = (8, -22, -35) + s(3, -11, -24)r(s)
= (3s + 8, -11s - 22, -24s - 35)
Linear approximation to the particle's trajectory at t
= 2:r(2 + h)
≈ (3h + 8, -11h - 22, -24h - 35).
Tangent to the curve at t = 2:r(s)
= (3s + 8, -11s - 22, -24s - 35).
To know more about Linear approximation, refer
https://brainly.com/question/30403460
#SPJ11
Reduce the equation to one of the standard forms, classify the surface, and sketch it.
33. y² = x² + 2²
34. 4x²y + 2z² = 0
35. x² + 2y 2z² = 0
36. y² = x² + 4z² + 4
37. x² + y² - 2x- 6y - z = 10 = 0
38. x² - y² - 2² - 4x2z + 3 = 0
39. x² - y² + 2² - 4x - 2z = 0
33. The equation is in the form of a hyperbolic equation: y² - x² = 4. It represents a hyperbolic curve with the center at the origin.
34. The equation represents an elliptic paraboloid. It can be written as 4x²y + 2z² = 0. The cross-sections parallel to the y-axis are ellipses, while the cross-sections parallel to the x-z plane are hyperbolas.
35. The equation represents an imaginary cone. It can be written as x² + 2y²z² = 0. The equation shows that the cone is symmetric with respect to the x-axis and opens upward.
36. The equation represents a hyperboloid of one sheet. It can be written as x² - y² - 4z² = -4. The hyperboloid opens upward and downward, and the cross-sections parallel to the x-y plane are hyperbolas.
37. The equation represents a sphere. It can be written as x² + y² - 2x - 6y - z = 10. The equation shows that the center of the sphere is (1, -3, 0) and the radius is √10.
38. The equation represents a hyperboloid of two sheets. It can be written as x² - y² - 4x²z + 3 = 0. The hyperboloid opens upward and downward, and the cross-sections parallel to the x-y plane are hyperbolas.
39. The equation represents an elliptic cone. It can be written as x² - y² + 4 - 4x - 2z = 0. The equation shows that the cone is symmetric with respect to the x-axis and opens upward. The cross-sections parallel to the x-z plane are ellipses.
To learn more about equation click here:brainly.com/question/29538993
#SPJ11
Give an example of a function between the groups Z6 and Z8 that
is not a homomorphism and why
The function f(x) = 2x does not preserve the group operation because f(ab) ≠ f(a)f(b).
Therefore, it is not a homomorphism.
The answer to this question is as follows:
Example of a function between the groups Z6 and Z8 that is not a homomorphism and why:
Let Z6 = {0, 1, 2, 3, 4, 5}, and
let Z8 = {0, 1, 2, 3, 4, 5, 6, 7}.
Let f: Z6 → Z8 be the function f(x) = 2x.
We show that f is not a homomorphism.
First of all, to show that f is not a homomorphism, we need to show that it does not preserve the group operation.
That is, we need to find elements a and b in Z6 such that f(ab) ≠ f(a)f(b).
Consider a = 2 and
b = 3
Then ab = 2 × 3
= 0 (mod 6)
Therefore, f(ab) = f(0)
= 0
On the other hand, f(a) = f(2)
= 4, and
f(b) = f(3)
= 6 (mod 8)
Hence, f(a)f(b) = 4 × 6
= 0 (mod 8).
Thus, we have f(ab) = 0
≠ 0
= f(a)f(b), and so f is not a homomorphism.
Basically, a homomorphism is a function between groups that preserves the group operation.
However, in this case, the function f(x) = 2x does not preserve the group operation because f(ab) ≠ f(a)f(b).
Therefore, it is not a homomorphism.
To know more about homomorphism, visit:
https://brainly.com/question/6111672
#SPJ11
Evaluate the integral ∫√4+x^3 dx as a power series and find its radius of convergence
The integral ∫√(4 + x^3) dx can be expressed as a power series using the binomial series expansion. The resulting series is 4^(1/2) * (x + (1/8)(x^4/4) - (3/128)(x^7/4^2) + ...). The radius of convergence for the power series is infinite, meaning that the series converges for all values of x.
To evaluate the integral, we first rewrite the integrand as (4 + x^3)^(1/2). Using the binomial series expansion, we expand (1 + x^3/4)^(1/2) into a series. Substituting this series back into the original integral, we obtain a power series representation for the integral.
The terms of the power series involve powers of (x^3/4), and to determine the radius of convergence, we apply the ratio test. Simplifying the ratio of successive terms, we find that the limit is 1/2. Since this limit is less than 1, the series converges for all values of x within a radius of convergence centered at x = 0. Therefore, the radius of convergence for the power series representation of the integral is infinite.
To know more about power series, click here: brainly.com/question/29896893
#SPJ11
suppose a circle has a circumference of 24 pi inches. what is the exact value of the circles diameter.
The exact value of the circle's diameter is 24 inches. The total distance around the outer boundary or perimeter of a circles is known as the circumference of a circle and it is a measure of the length of the circle.
The formula to find the diameter of a circle is given as;
Diameter of a circle = Circumference of a circle/π
The given circumference of a circle = 24π inches.
Diameter of the circle = (24π/π) inches = 24 inches.
Circumference is found by multiplying the diameter of the circle by mathematical constant pi (π), which is approximately 3.14159.
Therefore, the formula to calculate the circumference of a circle is:
Circumference = π × Diameter
Therefore, the exact value of the circle's diameter is 24 inches.
To know more about circle, refer
https://brainly.com/question/28162977
#SPJ11
. Assume two vector ả = [−1,−4,−5] and b = [6,5,4] a) Rewrite it in terms of i and j and k b) Calculated magnitude of a and b c) Express a + b and a - b in terms of i and j and k d) Calculate magnitude of a + b e) Show that a +b| ≤ |à| + | b| f) Calculate a b g) Find the angle between those two vector h) Calculate projection à on b. i) Calculate axb j) Evaluate the area of parallelogram defined by a and b
Given the vectors a = [-1, -4, -5] and b = [6, 5, 4], we can perform various operations on them.
a) Rewriting vector a in terms of i, j, and k:
a = -1i - 4j - 5k
b) Calculating the magnitude of vectors a and b:
|a| = √((-1)² + (-4)² + (-5)²) = √(1 + 16 + 25) = √42
|b| = √(6² + 5² + 4²) = √(36 + 25 + 16) = √77
c) Expressing a + b and a - b in terms of i, j, and k:
a + b = (-1 + 6)i + (-4 + 5)j + (-5 + 4)k = 5i + 1j - 1k
a - b = (-1 - 6)i + (-4 - 5)j + (-5 - 4)k = -7i - 9j - 9k
d) Calculating the magnitude of a + b:
|a + b| = √(5² + 1² + (-1)²) = √(25 + 1 + 1) = √27 = 3√3
e) Showing that |a + b| ≤ |a| + |b|:
|a + b| = 3√3 ≤ √42 + √77 ≈ 6.48
f) Calculating the dot product of a and b:
a · b = (-1)(6) + (-4)(5) + (-5)(4) = -6 - 20 - 20 = -46
g) Finding the angle between vectors a and b:
cosθ = (a · b) / (|a| |b|) = -46 / (√42 √77) ≈ -0.448
θ ≈ arccos(-0.448) ≈ 116.1°
h) Calculating the projection of a onto b:
proj_b(a) = (a · b / |b|²) b = (-46 / 77) [6, 5, 4] = [-276/77, -230/77, -184/77]
i) Calculating the cross product of a and b:
a x b = [(-4)(4) - (-5)(5)]i - [(-1)(4) - (-5)(6)]j + [(-1)(5) - (-4)(6)]k
= [-9, -10, 1]
j) Evaluating the area of the parallelogram defined by a and b:
Area = |a x b| = √((-9)² + (-10)² + 1²
Learn more about angle here:
https://brainly.com/question/31818999
#SPJ11
Let f(x) = 3 + x / 2−x
a) Determine the equation of the tangent line to f(x) at x =
10
In this problem, we are given the function f(x) = 3 + x / (2 - x). We need to determine the equation of the tangent line to f(x) at x = 10.
To find the equation of the tangent line to f(x) at x = 10, we first find the derivative of f(x) with respect to x, denoted as f'(x). The derivative represents the slope of the tangent line at any given point on the function.
Taking the derivative of f(x) using the quotient rule and simplifying, we obtain f'(x) = 5 / (2 - x)^2.
Next, we evaluate f'(x) at x = 10 to find the slope of the tangent line at that point. Substituting x = 10 into f'(x), we get f'(10) = 5 / (2 - 10)^2 = 5 / 64.
Now, we have the slope of the tangent line, and we also know that the tangent line passes through the point (10, f(10)). Substituting x = 10 into f(x), we find f(10) = 3 + 10 / (2 - 10) = -7.
Using the point-slope form of the equation of a line, which is y - y₁ = m(x - x₁), we can plug in the values of the slope (m = 5/64) and the point (x₁ = 10, y₁ = -7) to obtain the equation of the tangent line.
To learn more about quotient rule, click here:
brainly.com/question/30278964
#SPJ11
Solve the given system of equations by using the inverse of the coefficient matrix. Use a calculator to perform the necessary matrix operations
x1 + 4x2 - 3x3 - x4 =10
4x1 +x2 + x3 + 4x4 = 2
7x₁ - x₂ + x3 - x4 = -13
x1 - x2 - 3x3 - 2x4 = 3
The solution is x₁ = __ x₂= ___ x3 = __ and x4 = __
(Type integers or simplified fractions.)
The solution is x₁ = 2/139, x₂ = 8/139, x₃ = -16/139, and x₄ = 11/139.
We are given the following system of equations, which we have to solve using the inverse of the coefficient matrix.
x1 + 4x2 - 3x3 - x4 =10 ....(1)
4x1 + x2 + x3 + 4x4 = 2 ....(2)
7x₁ - x₂ + x3 - x4 = -13 ....(3)
x1 - x2 - 3x3 - 2x4 = 3 ....(4)
We need to find out x₁, x₂, x₃, and x₄. For that we will start with finding the inverse of the matrix A, where A is the coefficient matrix of the given system of equations.
ax1 + bx2 + cx3 + dx4 = y ⟶ equation (1)
ex1 + fx2 + gx3 + hx4 = z ⟶ equation (2)
ix1 + jx2 + kx3 + lx4 = m ⟶ equation (3)
px1 + qx2 + rx3 + sx4 = n ⟶ equation (4)
The above set of equations can be represented in the form of matrix as below:
[A][x] = [B]
where,[A] = [a b c d; e f g h; i j k l; p q r s]
[x] = [x1; x2; x3; x4]
[B] = [y; z; m; n]
Now, the inverse of matrix [A] is[A]⁻¹ = (1/|A|)[adj(A)]
where,|A| = determinant of matrix [A]
[adj(A)] = adjugate of matrix [A]
The adjugate of matrix [A] is obtained by taking the transpose of the cofactor matrix of [A].
Cofactor of each element aᵢₖ of [A] is Cᵢₖ = (-1)^(i+k) * Mᵢₖ
where, Mᵢₖ is the determinant of the submatrix of [A] obtained by deleting the i-th row and k-th column of [A].
Therefore, our first step will be to find the inverse of matrix A, which is shown below.
Given system of equations are:
x1 + 4x2 - 3x3 - x4 = 10
4x1 + x2 + x3 + 4x4 = 27
x₁ - x₂ + x3 - x4 = -13
x1 - x2 - 3x3 - 2x4 = 3
The coefficient matrix A is given by:
[A] = [1 4 -3 -1; 4 1 1 4; 7 -1 1 -1; 1 -1 -3 -2]
Using calculator, we will find the inverse of matrix A, as shown below:
[A]⁻¹ = 1/(|A|) * [adj(A)]
where,|A| = 278
adj(A) = transpose of cofactor matrix of [A]
[A]⁻¹ = 1/278 * [2 -5 2 -1; 13 10 -13 4; -11 21 -9 2; 8 -17 10 -3]
[x] = [x1; x2; x3; x4]
[B] = [10; 2; -13; 3]
Substituting the values, we have:
[A]⁻¹ [x] = [B]
Solving for [x], we get[x] = [A]⁻¹ [B]
We have already found the inverse of matrix A.
Now we will substitute the values in the above equation and find [x], which is shown below.
[x] = [2/139; 8/139; -16/139; 11/139]
Therefore, the solution is x₁ = 2/139, x₂ = 8/139, x₃ = -16/139, and x₄ = 11/139.
Learn more about coefficient matrix at:
https://brainly.com/question/13127746
#SPJ11
(Sections 2.11,2.12)
Calculate the equation for the plane containing the lines ₁ and ₂, where ₁ is given by the parametric equation
(x, y, z)=(1,0,-1) +t(1,1,1), t £ R
and l₂ is given by the parametric equation
(x, y, z)=(2,1,0) +t(1,-1,0), t £ R.
The equation for the plane containing lines ₁ and ₂ is: x - y - 2z = 3
To obtain the equation for the plane containing lines ₁ and ₂, we need to obtain a vector that is orthogonal (perpendicular) to both lines. This vector will serve as the normal vector to the plane.
First, let's find the direction vectors of lines ₁ and ₂:
Direction vector of line ₁ = (1, 1, 1)
Direction vector of line ₂ = (1, -1, 0)
To find a vector orthogonal to both of these direction vectors, we can take their cross product:
Normal vector = (1, 1, 1) × (1, -1, 0)
Using the cross product formula:
i j k
1 1 1
1 -1 0
= (1 * 0 - 1 * (-1), -1 * 1 - 1 * 0, 1 * (-1) - 1 * 1)
= (1, -1, -2)
Now that we have the normal vector, we can use it along with any point on one of the lines (₁ or ₂) to form the equation of the plane.
Let's use line ₁ and the point (1, 0, -1) on it.
The equation for the plane is given by:
Ax + By + Cz = D
Substituting the values we have:
1x + (-1)y + (-2)z = D
x - y - 2z = D
To find D, we substitute the coordinates of the point (1, 0, -1) into the equation:
1 - 0 - 2(-1) = D
1 + 2 = D
D = 3
Therefore, the equation is x - y - 2z = 3
To know more about plane containing lines refer here:
https://brainly.com/question/31732621#
#SPJ11
ii. Determine the regression model. O a. y = -12.09 +0.69x b. y = -13.11 +0.69x O c. y = -13.09 +0.69x O d. y = -11.09 +0.69x iii. Construct ANOVA table and perform hypothesis testing. O a. 4.67 > Fca
The question involves determining the regression model and performing hypothesis testing using an ANOVA table. The regression model is represented by the equation y = -12.09 + 0.69x.
To determine the regression model, you need to examine the given options and choose the equation that represents the relationship between the dependent variable (y) and the independent variable (x) based on the provided data. In this case, the regression model is given as y = -12.09 + 0.69x.
Next, you need to construct an ANOVA table to perform hypothesis testing. The ANOVA table provides information about the variation explained by the regression model and the residual variation. By comparing the calculated F-value (Fca) to the critical F-value, you can assess the significance of the regression model.
The given answer option "a. 4.67 > Fca" suggests that the calculated F-value is greater than the critical F-value, indicating that the regression model is statistically significant. This means that the independent variable (x) has a significant effect on the dependent variable (y) based on the provided data. By analyzing the ANOVA table and performing the hypothesis testing, you can determine the significance of the regression model and draw conclusions about the relationship between the variables.
Learn more about hypothesis testing here: brainly.com/question/17099835
#SPJ11
given that x =2 is a zero for the polynomial x3-28x 48, find the other zeros
The zeros of the polynomial x³ - 28x + 48 are 2, -6, and 4.
Given that x = 2 is a zero for the polynomial x3 - 28x + 48, we need to find the other zeros.
Using the factor theorem, (x - a) is a factor of the polynomial if and only if a is a zero of the polynomial.
Therefore, we have(x - 2) as a factor of the polynomial.
Dividing x³ - 28x + 48 by (x - 2), we get the quadratic equation:x² + 2x - 24 = 0
We can now factorize the quadratic expression as: (x + 6)(x - 4) = 0
Thus, the other zeros of the polynomial are x = -6 and x = 4.
Therefore, the zeros of the polynomial x³ - 28x + 48 are 2, -6, and 4.
Know more about polynomial here:
https://brainly.com/question/1496352
#SPJ11
Given the normal distribution N(10,2), draw the curves and use the following to answer the questions: a) Using the 68-95-99.7 rule, what is P(X<8)? b) Using the z-table, what is P(X<6.52)
a) Using the 68-95-99.7 rule, P(X < 8) can be calculated as approximately 0.1587. b) Using the z-table, P(X < 6.52) can be determined by finding the corresponding z-score and looking up the probability associated with that z-score.
a) The 68-95-99.7 rule states that for a normal distribution, approximately 68% of the data falls within one standard deviation of the mean, 95% falls within two standard deviations, and 99.7% falls within three standard deviations. Since we are given a normal distribution N(10,2), where 10 is the mean and 2 is the standard deviation, we can infer that P(X < 8) corresponds to the area under the curve to the left of 8. By using the 68-95-99.7 rule, we know that 68% of the data falls within one standard deviation of the mean, and since the distribution is symmetric, approximately half of that 68% is to the left of the mean. Therefore, P(X < 8) is approximately 0.5 minus half of the remaining 68%, which gives us an approximate value of 0.1587.
b) To find P(X < 6.52) using the z-table, we need to convert the value 6.52 into a z-score. The z-score measures the number of standard deviations a value is away from the mean in a standard normal distribution (mean = 0, standard deviation = 1). We can calculate the z-score using the formula z = (x - μ) / σ, where x is the given value, μ is the mean, and σ is the standard deviation. In this case, since we are given a normal distribution N(10,2), the z-score can be calculated as z = (6.52 - 10) / 2. Once we have the z-score, we can look it up in the z-table to find the corresponding probability. The probability P(X < 6.52) represents the area under the curve to the left of 6.52.
To know more about probability,
https://brainly.com/question/13946133
#SPJ11
Find the difference quotient and simplify your answer. f(x)-f(64) f(x) = x2/3 + 4, x # 64 X-64
The difference quotient of f(x) = x^(2/3) + 4, evaluated at x = 64, is (64^(2/3) + 4 - f(64))/(x - 64).
What is the difference quotient of the function f(x) = x^(2/3) + 4 at x = 64?
Learn more about the concept of the difference quotient and its application in finding the rate of change of a function below.
The difference quotient is a mathematical expression used to determine the rate of change of a function at a specific point. It measures the average rate of change of a function over a small interval.
Given the function f(x) = x^(2/3) + 4, we want to find the difference quotient when x = 64. To calculate the difference quotient, we subtract the value of the function at x = 64 (f(64)) from the general expression of the function (f(x)).
The general expression of the function is f(x) = x^(2/3) + 4. Evaluating f(64), we substitute x = 64 into the function:
f(64) = 64^(2/3) + 4.
Substituting these values into the difference quotient formula, we have:
(64^(2/3) + 4 - f(64))/(x - 64).
Simplifying further would involve evaluating 64^(2/3) and simplifying any potential common factors between the numerator and denominator.
Learn more about the concept of the difference quotient and its application in finding the rate of change of a function.
#SPJ11
Identify The information given to YOu in the application problem below. Use that information to answer the questions that follow Round your answers t0 two decimal places aS needed He decided to use it to Tim found piggY bank in the back of his closet that he hadn"t seen in years_ the bank every month_ After three months,_ save up fOr summer vacation by depositing S81 in pIggY counted the amount %f money in the Diggy bank and found he had 267 dollars did Tim have the piggy bank before he started making monthly deposits? How much money in the piggy bank before he started making monthly deposits Tim had Write your function in the form of $' mt Write Linear Function that represents this situation_ represents the amount of money in the piggy bank after months of saving where Linear Function: Find the value of where $ 753 Write your Tim decides he needs 753 dollars for his vacation- answer as an Ordered Pair; to expiain the meaning of the Ordered Pair. Complete the following sentence months. Timn will have enough money After depositing S81 per month for for his vacation.
Tim found a piggy bank in the back of his closet that he hadn't seen in years. He decided to use it to save up for summer vacation by depositing $81 in a piggy bank every month. After three months, Tim counted the amount of money in the piggy bank and found he had $267.
1. To find the initial amount of money in the piggy bank before Tim started making monthly deposits, we can subtract the total amount saved after three months ($267) from the amount saved each month for three months ($81/month * 3 months):
Initial amount = Total amount - Amount saved each month * Number of months
Initial amount = $267 - ($81/month * 3 months)
Initial amount = $267 - $243
Initial amount = $24
2. The linear function that represents the amount of money in the piggy bank after "months" of saving can be expressed as:
Amount = Initial amount + Monthly deposit * Number of months
Amount = $24 + $81 * months
3. To find the value of "months" when Tim will have enough money ($753) for his vacation, we can set up the equation:
$24 + $81 * months = $753
Solving this equation for "months," we get:
$81 * months = $753 - $24
$81 * months = $729
months = $729 / $81
months = 9
Therefore, the ordered pair representing the value of "months" when Tim will have enough money for his vacation is (9, $753).
4. The ordered pair (9, $753) means that after saving for 9 months, Tim will have enough money ($753) in the piggy bank to cover the cost of his vacation.
To know more about Piggy Bank visit:
https://brainly.com/question/29863158
#SPJ11
Consider the following linear programming problem. Max 5X; + 6X2 Objective function s.t. X: + X2 560 Constraint 1 5X, +7X, S 350 Constraint 2 X; s 50 Constraint 3 X, X, 20 80 75 Exam HH100503 Exam SEHHI am 70 65 60 Line 2 55 50 45 40 35 30 25 20 15 Line 4 10 Line 3 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 (a) Classify which constraints belong to line 1, line 2 and line 3 respectively. (3 marks) (b) Find the optimal solution and the optimal value of the objective fimction. (4 marks) (c) If the coefficient of Xz of the objective function changes from 6 to (6.1 + 0.1 T). Is the solution found in part 6) still optimal? Determine the new optimal value. (1 marks) (d) Find the dual price if the right-hand side for constraint I increases from 60 to 61. (6 marks) Correct your final answers to I decimal place whenever appropriate.
a) Constraints for line 1, line 2, and line 3 are 5X1 + 7X2 ≤ 350, X2 ≤ 50, and 2X1 + 5X2 ≤ 80 respectively.
b) Optimal solution is (X1 = 60, X2 = 20) and optimal value is 420.
c) The new optimal solution point is (X1 = 59.147, X2 = 20.678) and the new optimal value is (6.1 + 0.1T)(20.678) + 5(59.147)
d) Dual price of constraint 2X1 + 5X2 ≤ 80 is 5 when RHS is increased from 60 to 61.
a) Classify which constraints belong to line 1, line 2, and line 3 respectively:
The optimal solution of the given linear programming problem can be found using the graphical method as given below:
Line 1 represents the constraint 5X1 + 7X2 ≤ 350Line 2 represents the constraint X2 ≤ 50Line 3 represents the constraint 2X1 + 5X2 ≤ 80
b) The optimal solution and the optimal value of the objective function are:X1 = 60, X2 = 20Optimal value = 5(60) + 6(20) = 420
c) If the coefficient of X2 of the objective function changes from 6 to (6.1 + 0.1 T).
When the coefficient of X2 in the objective function changes from 6 to (6.1 + 0.1T), then the optimal solution point changes. The optimal solution point after the change in the coefficient of X2 in the objective function is given below:X1 = 59.147, X2 = 20.678
Optimal value = 5(59.147) + (6.1 + 0.1T)(20.678)
d) Find the dual price if the right-hand side for constraint I increases from 60 to 61.The optimal solution of the given linear programming problem is:X1 = 60, X2 = 20
Therefore, the slack value for the constraint 2X1 + 5X2 ≤ 80 is zero. This means that the dual price of the constraint 2X1 + 5X2 ≤ 80 is equal to the coefficient of X1 in the objective function. Dual price = 5
Know more about the linear programming
https://brainly.com/question/14309521
#SPJ11
Use mathematical induction to show that derivative of f(x) = x" equals nx"-1 whenever n is a positive integer.
By mathematical induction, it has been proved that the derivative of f(x) = x" equals nx"-1 whenever n is a positive integer.
The given function is f(x) = x" and it is required to show that the derivative of the given function f(x) is nx"-1 whenever n is a positive integer by mathematical induction.
Mathematical induction is a technique to prove a statement for all positive integers. The proof is done by showing that the statement is true for n = 1 and then showing that if it is true for any positive integer k, then it is also true for k + 1.
Now, let's prove the statement that the derivative of f(x) = x" equals nx"-1 whenever n is a positive integer by mathematical induction.
1: Base Case
For n = 1, f(x) = x¹, and its derivative is f '(x) = 1 × x¹⁻¹ = 1 × x⁰ = 1 = 1x¹⁻¹ which is the same as nx"-1 when n = 1.
So, the statement is true for n = 1.
2: Inductive Hypothesis
Assume that the statement is true for n = k, which is,d/dx (xk) = kxk-1 ----(1)
Now, it is required to show that the statement is also true for n = k + 1, which is,d/dx (xk+1) = (k+1)xk ----(2)
3: Inductive Step
The derivative of f(x) = xk+1 is given by,d/dx (xk+1) = d/dx (xk × x) = xk d/dx (x) + x d/dx (xk) = xk × 1 + x × kxk-1 (using the Inductive Hypothesis from equation (1))= xk + kxk = (k+1) × xk
Therefore, d/dx (xk+1) = (k+1)xk, which is the same as nx"-1 when n = k + 1.
So, the statement is true for n = k + 1.
Learn more about equation at;
https://brainly.com/question/10413253
#SPJ11
Let x and y be vectors for comparison: x = (4, 20) and y = (18, 5). Compute the cosine similarity between the two vectors. Round the result to two decimal places.
The cosine similarity between the vectors x = (4, 20) and y = (18, 5) is approximately 0.21.
Cosine similarity measures the similarity between two vectors by calculating the cosine of the angle between them. The formula for cosine similarity is given by cosine similarity = (x · y) / (||x|| * ||y||),
where x · y represents the dot product of x and y, and ||x|| and ||y|| denote the magnitudes of x and y, respectively. In this case, the dot product of x and y is 418 + 205 = 72 + 100 = 172, and the magnitudes of x and y are √(4² + 20²) ≈ 20.396 and √(18²+ 5²) ≈ 18.973, respectively .Thus, the cosine similarity is approximately 172 / (20.396 * 18.973) ≈ 0.21, rounded to two decimal places.
Learn more about vectors click here:
brainly.com/question/24256726
#SPJ11
Exercise 6
Given the demand function P = 1000-Q express TR as a function of Q and hence sketch a graph of TR against Q. What value of Q maximizes total revenue and what is the corresponding price?
Exercise 7
Given that fixed costs are 100 and that variable costs are 2 per unit, express TC and AC as functions of Q. Hence sketch their graphs.
Exercise 8
If fixed costs are 25, variable costs per unit are 2 and the demand function is P=20-Q obtain an expression for π in terms of Q and hence sketch its graph.
(a) Find the levels of output which give a profit of 31.
(b) Find the maximum profit and the value of Q at which it is achieved.
Exercise 6 : The value of Q that maximizes total revenue is 500. Exercise 7: AC = (100 + 2Q)/Q. Exercise 8: (a) The levels of output that give a profit of 31 are 14.5 and 3.5 ; (b) The maximum profit is 81 and the value of Q at which it is achieved is 9.
Exercise 6 :
Given the demand function P = 1000-Q express TR as a function of Q and sketch a graph of TR against Q.
Total Revenue (TR) is calculated by multiplying the price (P) with the quantity demanded (Q).
P= 1000-Q, so the equation for Total Revenue will be:
TR= P x Q
= (1000-Q) Q
= 1000Q - Q²
We can see that the Total Revenue is maximized when Q = 500, so we have to find the price corresponding to it.
Now, when Q = 500,
P = 1000 - Q =
1000 - 500
= 500
Therefore, the value of Q that maximizes total revenue is 500 and the corresponding price is 500.
Exercise 7: Given that fixed costs are 100 and that variable costs are 2 per unit, express TC and AC as functions of Q and hence sketch their graphs.
Total Cost (TC) = Fixed Cost (FC) + Variable Cost (VC) x Quantity demanded (Q)
TC = 100 + 2Q
Also, Average Cost (AC) = Total Cost (TC) / Quantity demanded (Q)
AC = (100 + 2Q)/Q
Exercise 8: If fixed costs are 25, variable costs per unit are 2, and the demand function is P=20-Q, obtain an expression for π in terms of Q and sketch its graph.
Profit (π) is calculated by subtracting the Total Cost (TC) from the Total Revenue (TR).
TR = P x Q
= (20 - Q)Q
= 20Q - Q²
TC = FC + VC x Q
= 25 + 2Q
Therefore,
π = TR - TC
= (20Q - Q²) - (25 + 2Q)
= - Q² + 18Q - 25
a) Find the levels of output which give a profit of 31.
π = - Q² + 18Q - 25
Let's set
π = 31.- Q² + 18Q - 25
= 31- Q² + 18Q - 56
= 0
Now, we can solve this quadratic equation to get the values of Q.
Q = [18 ± √(18² - 4(-1)(-56))]/2Q
= [18 ± 10√10]/2Q
= 9 ± 5√10
Therefore, the levels of output that give a profit of 31 are approximately 14.5 and 3.5
b) Find the maximum profit and the value of Q at which it is achieved.
π = - Q² + 18Q - 25
We can find the value of Q that maximizes profit by using the formula
Q = - b/2a (where a = -1, b = 18)
Q = -18 / 2(-1)
= 9
Now, we can find the maximum profit by substituting Q = 9 in the expression for π.
π = - Q² + 18Q - 25
= - 9² + 18(9) - 25
= 81
Therefore, the maximum profit is 81 and the value of Q at which it is achieved is 9.
Know more about the demand function
https://brainly.com/question/13865842
#SPJ11
Find the area enclosed by the curve y=1/1+3 above the x axis between the lines x=2 and x=3.
The area enclosed by the curve y = 1/(1 + 3x) above the x-axis between the lines x = 2 and x = 3 is (1/3) ln(4/7).
To find the area enclosed by the curve y = 1/(1 + 3x) above the x-axis between the lines x = 2 and x = 3, we can calculate the definite integral of the function within the given interval.
The definite integral for the area can be expressed as:
A = ∫[2, 3] (1/(1 + 3x)) dx
To solve this integral, we can use the substitution method. Let u = 1 + 3x, then du = 3 dx. Rearranging the equation, we have dx = du/3.
Substituting the values, the integral becomes:
A = ∫[2, 3] (1/u) (du/3)
A = (1/3) ∫[2, 3] du/u
A = (1/3) ln|u| |[2, 3]
Now, substituting back u = 1 + 3x, we have:
A = (1/3) ln|1 + 3x| |[2, 3]
Evaluating the integral within the given limits, we get:
A = (1/3) ln|4| - (1/3) ln|7|
Simplifying further, we have:
A = (1/3) ln(4/7)
Visit here to learn more about curve:
brainly.com/question/29364263
#SPJ11
Random variables X and Y have joint probability density function (PDF),
fx,y (x,y) = { ce^-(2x+3y), x ≥ 0, y ≥ 0
0, otherwise
where c is a constant. Let A be the event that X + Y ≤ 1. Determine the conditional PDF fx,y|A(x,y).
The conditional PDF fx,y|A(x,y) is: $$f_{X, Y \mid A}(x, y) = \begin{cases}\frac{9}{10e^7 - 20e^5 + 6e^2} e^{-(2x + 3y)} & \text{if } 0 \leq x \leq 1 \text{ and } 0 \leq y \leq 1 - x \\0 & \text{otherwise} \end{cases}$$.
We are given that random variables X and Y have joint probability density function (PDF):
[tex]f X,Y (x,y)={ ce −(2x+3y) 0 if x≥0 and y≥0otherwise[/tex]
where c is a constant. Let A be the event that X + Y ≤ 1. We are to determine the conditional PDF f(x, y | A).
So, we have to calculate:
[tex]f X,Y∣A (x,y)[/tex]
Using Bayes' theorem, we have:
[tex]f X,Y∣A (x,y)= P(A)P(A∣X=x,Y=y)f X,Y (x,y)[/tex]
Now, we will calculate each of these probabilities separately:
For P(A), let's find the range of values for x and y that satisfy X + Y ≤ 1. We have:
[tex]X + Y &\leq 1 \\Y &\leq 1 - X\end{aligned}$$[/tex]
For Y ≥ 0, we must have 0 ≤ X ≤ 1. Therefore, the region in the (x, y) plane that satisfies X + Y ≤ 1 is the triangle with vertices (0, 0), (1, 0), and (0, 1).
Hence, we have:
[tex]$$P(A) = \iint_{A} f_{X, Y}(x, y)\,dx\,dy$$$$\begin{aligned}P(A) &= \int_{0}^{1} \int_{0}^{1 - x} ce^{-(2x + 3y)}\,dy\,dx \\&= \int_{0}^{1} \left[-\frac{c}{3}e^{-(2x + 3y)}\right]_{y=0}^{y=1-x}dx \\&= \int_{0}^{1} \frac{c}{3}(e^{-2x} - e^{-5x})dx \\&= \frac{c}{3}\left[-\frac{1}{2}e^{-2x} + \frac{1}{5}e^{-5x}\right]_{x=0}^{x=1} \\&= \frac{c}{3}\left(\frac{1}{10} - \frac{1}{2e^2} + \frac{1}{5e^5}\right) \\&= \frac{c}{3}\left(\frac{10e^7 - 20e^5 + 6e^2}{100e^7}\right)\end{aligned}$$[/tex]
Now, we will find P(A | X = x, Y = y). We have:
[tex]$$\begin{aligned}P(A \mid X = x, Y = y) &= P(X + Y \leq 1 \mid X = x, Y = y) \\&= P(Y \leq 1 - x \mid X = x, Y = y) \\&= 1_{0 \leq x \leq 1} \cdot 1_{0 \leq y \leq 1 - x}\end{aligned}$$[/tex]
where 1 is the indicator function. That is, it is equal to 1 if the argument is true, and 0 otherwise.
Finally, we can find fX,Y|A(x, y) using the formula above. We get:
[tex]$$\begin{aligned}f_{X, Y \mid A}(x, y) &= \frac{P(A \mid X = x, Y = y)f_{X, Y}(x, y)}{P(A)} \\&= \frac{1_{0 \leq x \leq 1} \cdot 1_{0 \leq y \leq 1 - x} ce^{-(2x + 3y)}}{\frac{c}{3}\left(\frac{10e^7 - 20e^5 + 6e^2}{100e^7}\right)} \\&= \frac{9}{10e^7 - 20e^5 + 6e^2} \cdot e^{-(2x + 3y)} \cdot 1_{0 \leq x \leq 1} \cdot 1_{0 \leq y \leq 1 - x}\end{aligned}$$[/tex]
Therefore, the conditional PDF fx,y|A(x,y) is:
[tex]$$f_{X, Y \mid A}(x, y) = \begin{cases}\frac{9}{10e^7 - 20e^5 + 6e^2} e^{-(2x + 3y)} & \text{if } 0 \leq x \leq 1 \text{ and } 0 \leq y \leq 1 - x \\0 & \text{otherwise} \end{cases}$$[/tex]
To learn more about conditional, refer below:
https://brainly.com/question/19258518
#SPJ11
The conditional probability density function (PDF) fx,y|A(x,y) for random variables X and Y,
To find the conditional PDF fx,y|A(x,y), we need to normalize the joint PDF fx,y(x,y) over the region defined by A, which is X + Y ≤ 1. The joint PDF fx,y(x,y) is given as ce^-(2x+3y) for x ≥ 0 and y ≥ 0, and 0 otherwise.
To normalize the joint PDF over the region A, we integrate the joint PDF over the region where X + Y ≤ 1. The limits of integration will depend on the values of x and y in the given region. The resulting normalized PDF will give us the conditional PDF fx,y|A(x,y).
The specific calculation of the integral and the resulting conditional PDF would require more information about the region A, such as its shape and limits. Without this information, it is not possible to provide the exact mathematical expression for fx,y|A(x,y). However, the process of obtaining the conditional PDF involves normalizing the joint PDF over the region defined by the event A, which can be done using the given joint PDF and the limits of integration.
To learn more about probability Here :
brainly.com/question/31828911
#SPJ11
A professor wants to find out if she can predict exam grades from how long it takes students to finish them. She examined a sample of 10 students previous exam scores and times it took them to complete previous exams. The mean time was 48.50 minutes, and the standard deviation for time was 16.46. The mean exam score was 78.70, and the standard deviation for exam score was 11.10. The Pearson's r between exam scores and length of time taken to complete the exam was r= -89, and this correlation was significant.
Pearson's r correlation coefficient value of -89 suggests that exam grades and length of time taken to complete the exam are negatively correlated.
The Pearson's r correlation between exam scores and length of time taken to complete the exam.Pearson's r correlation coefficient is a method that allows one to determine the strength and direction of the relationship between two variables.
The Pearson's r correlation coefficient between exam scores and the length of time it took students to complete them was -89, indicating that there was a strong negative correlation between these two variables. This means that as the time it takes students to complete the exam increases, the exam scores decrease.
The correlation was also significant, indicating that the relationship between the two variables is unlikely to have occurred by chance.The mean time taken by the students to complete the exam was 48.50 minutes, and the standard deviation was 16.46. The mean exam score was 78.70, and the standard deviation for exam score was 11.10.
To know more about correlation coefficient visit:
brainly.com/question/29704223
#SPJ11
If the correlation coefficient between two variables is -0.6, then
a.
the coefficient of determination of the regression analysis must be 0.36.
b.
the coefficient of determination of the regression analysis must be -0.36.
c.
the coefficient of determination of the regression analysis must be 0.6.
d.
the coefficient of determination of the regression analysis must be -0.6.
The correct option is (a) the coefficient of determination of the regression analysis must be 0.36.
The coefficient of determination (R-squared) is the square of the correlation coefficient (r). In this case, since the correlation coefficient is -0.6, squaring it gives us 0.36. The coefficient of determination represents the proportion of the variance in the dependent variable that can be explained by the independent variable(s) in a regression analysis. Therefore, if the correlation coefficient is -0.6, the coefficient of determination must be 0.36, indicating that 36% of the variance in the dependent variable is explained by the independent variable(s).
To know more about correlation coefficients here: brainly.com/question/29704223
#SPJ11
Consider the following.
f(x) = { e^x if x < 1 a =1
x^3 if x ≥ 1
Find the left-hand and right-hand limits at the given value of a.
lim x -> 1 f(x) = ___________
lim x -> 1 f(x) = ___________
Explain why the function is discontinous at the given number a.
The left-hand limit of f(x) as x approaches 1 is e^1, which is approximately 2.71828. The right-hand limit of f(x) as x approaches 1 is 1^3, which is equal to 1.
The function is discontinuous at x = 1 because the left-hand limit (e^1) is not equal to the right-hand limit (1^3). In order for a function to be continuous at a specific point, the left-hand limit and the right-hand limit must be equal. However, in this case, the function takes on different values depending on whether x is less than 1 or greater than or equal to 1.
When x is less than 1, the function takes on the value of e^x, which approaches approximately 2.71828 as x approaches 1 from the left. On the other hand, when x is greater than or equal to 1, the function takes on the value of x^3, which equals 1 when x is 1. Therefore, the function has a jump discontinuity at x = 1.
The jump discontinuity occurs because the function "jumps" from one value to another at x = 1, without any intermediate values. This violates the definition of continuity, which requires the function to have a single, well-defined value at each point. Thus, the function is discontinuous at x = 1.
Learn more about limit here: brainly.com/question/12211820
#SPJ11
Find the point(s) on the curve where the tangent line is horizontal. Then, find the point(s) on the curve where the tangent line is vertical. Show all work x = 1+cost y=1-sint' for 0≤t≤ 2π
To find the points on the curve where the tangent line is horizontal or vertical, we need to find the derivative of the curve and set it equal to zero for horizontal tangents.
To find the points where the derivative is undefined for vertical tangents.
Given the parametric equations:
x = 1 + cos(t)
y = 1 - sin(t)
Let's find the derivative of y with respect to x using the chain rule:
dy/dx = (dy/dt) / (dx/dt)
To find dy/dt and dx/dt, we differentiate each equation with respect to t:
dx/dt = -sin(t) (derivative of cos(t) is -sin(t))
dy/dt = -cos(t) (derivative of -sin(t) is -cos(t))
Now, we can calculate dy/dx:
dy/dx = (dy/dt) / (dx/dt) = (-cos(t)) / (-sin(t)) = cos(t) / sin(t)
To find the points where the tangent line is horizontal, we set dy/dx equal to zero:
cos(t) / sin(t) = 0
Since sin(t) cannot be zero (as it would lead to division by zero), we conclude that the tangent line is horizontal when cos(t) = 0.
The values of t that satisfy cos(t) = 0 are t = π/2 and t = 3π/2.
Now, let's find the corresponding points on the curve:
For t = π/2:
x = 1 + cos(π/2) = 1
y = 1 - sin(π/2) = 1 - 1 = 0
For t = 3π/2:
x = 1 + cos(3π/2) = 1
y = 1 - sin(3π/2) = 1 + 1 = 2
Therefore, the points on the curve where the tangent line is horizontal are (1, 0) and (1, 2).
To find the points where the tangent line is vertical, we need to determine where the derivative dy/dx is undefined. This occurs when the denominator of dy/dx is zero: sin(t) = 0
The values of t that satisfy sin(t) = 0 are t = 0 and t = π.
Now, let's find the corresponding points on the curve:
For t = 0:
x = 1 + cos(0) = 1 + 1 = 2
y = 1 - sin(0) = 1 - 0 = 1
For t = π:
x = 1 + cos(π) = 1 - 1 = 0
y = 1 - sin(π) = 1 - 0 = 1
Therefore, the points on the curve where the tangent line is vertical are (2, 1) and (0, 1).
In summary, the points on the curve where the tangent line is horizontal are (1, 0) and (1, 2), while the points where the tangent line is vertical are (2, 1) and (0, 1).
To learn more about tangent line visit:
brainly.com/question/32252327
#SPJ11
Use the linear approximation formula
∆y = f'(x) ∆r
or
f(x + ∆r) ≈ f(x) + f'(x) ∆r
with a suitable choice of f(x) to show that
t^θ² ≈1+θ² for small values of θ.
Using the linear approximation formula, we can show that for small values of θ, the expression t^θ² is approximately equal to 1 + θ². This approximation holds when θ is close to zero.
To apply the linear approximation formula, we choose f(x) = x^θ² and consider a small change ∆r in the variable x. According to the linear approximation formula, f(x + ∆r) ≈ f(x) + f'(x) ∆r.Taking the derivative of f(x) = x^θ² with respect to x, we have f'(x) = θ²x^(θ² - 1). Now, let's evaluate the expression f(x + ∆r) using the linear approximation formula:
f(x + ∆r) ≈ f(x) + f'(x) ∆r
(x + ∆r)^θ² ≈ x^θ² + θ²x^(θ² - 1) ∆r.
When θ is small (close to zero), we can neglect higher-order terms involving θ² or higher powers of θ. Thus, we can approximate x^(θ² - 1) as 1 since the exponent θ² - 1 will be close to zero. Simplifying the expression, we have:
(x + ∆r)^θ² ≈ x^θ² + θ² ∆r.
Now, we substitute t for x and ∆y for (x + ∆r)^θ² to match the given expression t^θ². This gives us:
t^θ² ≈ f(t + ∆r) ≈ f(t) + f'(t) ∆r
≈ t^θ² + θ² ∆r.
Since θ is small, the term θ² ∆r can be considered negligible. Therefore, we have:t^θ² ≈ t^θ² + θ² ∆r ≈ t^θ² + 0 ≈ t^θ².
Hence, for small values of θ, we can approximate t^θ² as 1 + θ².
To learn more about linear approximation click here :
brainly.com/question/30403460
#SPJ11