Answer: a. CI for the mean: 17.327 < μ < 26.473
b. CI for variance: 29.7532 ≤ [tex]\sigma^{2}[/tex] ≤ 170.9093
Step-by-step explanation:
a. To construct a 95% confidence interval for the mean:
The given data are:
mean = 21.9
s = 7.7
n = 12
df = 12 - 1 = 11
1 - α = 0.05
[tex]\frac{\alpha}{2}[/tex] = 0.025
t-score = [tex]t_{0.025,11}[/tex] = 2.2001
Note: since the sample population is less than 30, it is used a t-score.
The formula for interval:
mean ± [tex]t.\frac{s}{\sqrt{n} }[/tex]
Substituing values:
21.9 ± 2.200.[tex]\frac{7.7}{\sqrt{12} }[/tex]
21.9 ± 4.573
The interval is: 17.327 < μ < 26.473
b. A 95% confidence interval for the variance:
The given values are:
[tex]s^{2}[/tex] = [tex]7.7^{2}[/tex]
[tex]s^{2}[/tex] = 59.29
α = 0.05
[tex]\frac{\alpha}{2}[/tex] = 0.025
[tex]1-\frac{\alpha}{2}[/tex] = 0.975
[tex]\chi^{2}_{0.025,11}[/tex] = 21.92
[tex]\chi^{2}_{0.975,11}[/tex] = 3.816
Note: To find the values for [tex]\chi^{2}_{\alpha/2,n-1}[/tex] and [tex]\chi^{2}_{1-\alpha/2,n-1}[/tex], look for them at the chi-square table
The formula to calculate interval:
([tex]\frac{(n-1).s^{2}}{\chi^{2}_{\alpha/2,n-1}} , \frac{(n-1)s^{2}}{\chi^{2}_{1-\alpha/2,n-1}}[/tex])
are the lower and upper limits, respectively.
Substituing values:
([tex]\frac{11.59.29}{21.92} , \frac{11.59.29}{3.816}[/tex])
(29.7532, 170.9093)
The interval for variance is: 29.7532 ≤ [tex]\sigma^{2}[/tex] ≤ 170.9093
What is the value of x? The figure contains 2 lines that intersect to form what looks like an x. Two of the 4 angles in the x are labeled. The left angle is labeled open parenthesis 3 x minus 3 close parenthesis degrees. The right angle across from it is labeled open bracket 6 open parenthesis x minus 10 close parenthesis close bracket degrees. Enter your answer in the box. x =
Answer:
[tex]x=38.5^\circ[/tex]
Step-by-step explanation:
Given that the left angle = [tex](3x-3)^\circ[/tex]
The right angle across from it [tex]= 6(x-10)^\circ[/tex]
The other two angles are x and x.
We know that the sum of angles at a point equals 360 degrees.
Therefore,
[tex](3x-3)^\circ+6(x-10)^\circ+x+x=360^\circ\\3x-3+6x-60+2x=360\\11x-63=360\\11x=360+63\\11x=423\\x=38.5^\circ[/tex]
The value of x is approximately 38.5 degrees.
A poll found that 5% of teenagers (ages 13 to 17) suffer from arachnophobia and are extremely afraid of spiders. At a summer camp there are 11 teenagers sleeping in each tent. Assume that these 11 teenagers are independent of each other. (Round your answers to four decimal places.)
a) Calculate the probability that at least one of them suffers from arachnophobia. - 0.4312
b) Calculate the probability that exactly 2 of them suffer from arachnophobia? 0.08666
c) Calculate the probability that at most 1 of them suffers from arachnophobia? What is C?
Answer:
a) Calculate the probability that at least one of them suffers from arachnophobia.
x = number of students suffering from arachnophobia
= P(x ≥ 1)
= 1 - P(x = 0)
= 1 - [0.05⁰ x (1 - 0.05)¹¹⁻⁰ ]
= 1 - (0.95)¹¹
= 0.4311999 = 0.4312
b) Calculate the probability that exactly 2 of them suffer from arachnophobia? 0.08666
= P(x = 2)
= (¹¹₂) x (0.05)² x (0.95)⁹
where ¹¹₂ = 11! / (2!9!) = (11 x 10) / (2 x 1) = 55
= 55 x 0.0025 x 0.630249409 = 0.086659293 = 0.0867
c) Calculate the probability that at most 1 of them suffers from arachnophobia?
P(x ≤ 1)
= P(x = 0) + P(x = 1)
= [(¹¹₀) x 0.05⁰ x 0.95¹¹] + [(¹¹₁) x 0.05¹ x 0.95¹⁰]
= (1 x 1 x 0.5688) + (11 x 0.05 x 0.598736939) = 0.5688 + 0.3293 = 0.8981
Please answer this correctly
Answer:
The first answer.
Step-by-step explanation:
The first answer.
What was the temperature of the air?
'was 2C warmer than the surface of the ice'
warmer than= +2c
Temp. of ice=-2c
-2c+2c=0
Answer:
Option 1
Step-by-step explanation:
The temp. was -2 degrees celsius.
The temp. got 2 degrees celsius warmer.
-2 + 2 = 0
cos3x-3cosx=cos2x+1 {Domain: 0<=x<=360} The solution is 90deg, 180deg, and 270deg, but what are the simplifying steps in between? I know all trig identities.
Step-by-step explanation:
cos(3x) − 3 cos x = cos(2x) + 1
Use triple and double angle formulas.
(4 cos³x − 3 cos x) − 3 cos x = (2 cos²x − 1) + 1
Simplify.
4 cos³x − 6 cos x = 2 cos²x
4 cos³x − 2 cos²x − 6 cos x = 0
2 cos³x − cos²x − 3 cos x = 0
Factor.
cos x (2 cos²x − cos x − 3) = 0
cos x (cos x + 1) (2 cos x − 3) = 0
Solve.
cos x = 0 → x = 90°, 270°
cos x + 1 = 0 → x = 180°
2 cos x − 3 = 0 → no solution
Scores on the SAT test have a mean of 1518 and a standard deviation of 325. Scores on the ACT test have a mean of 21.1 and a standard deviation of 4.8. Which of the following choices is not true?
A. The ACT score gt 17.0 is relatively better than the SAT score of 1490 a relatively better then the SAT score of 1490 .
B. An SAT score of 1490 has a z-score of -0.09
C. The SAT score of 1490 is relatively better than the ACT score of 17.0.
Answer:
The ACT score gt 17.0 is relatively better than the SAT score of 1490 a relatively better then the SAT score of 1490 .
Step-by-step explanation:
Z-score:
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
A. The ACT score gt 17.0 is relatively better than the SAT score of 1490 a relatively better then the SAT score of 1490.
We find the z-score for each of these options. Whichever has the higher z-score is the better grade.
ACT:
Mean 21.1, standard deviation of 4.8. Score of 17. So [tex]\mu = 21.1, \sigma = 4.8, X = 17[/tex]
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{17 - 21.1}{4.8}[/tex]
[tex]Z = -0.85[/tex]
SAT:
Scores on the SAT test have a mean of 1518 and a standard deviation of 325. Score of 1490. So [tex]\mu = 1518, \sigma = 325, X = 1490[/tex]
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{1490 - 1518}{325}[/tex]
[tex]Z = -0.09[/tex]
The SAT score of 1490 has the higher z-score, so this is the better score, which means that this statement is false and A. is the answer of this question.
B. An SAT score of 1490 has a z-score of -0.09
From A., this is true
C. The SAT score of 1490 is relatively better than the ACT score of 17.0.
From A., this is true.
Please help need to do corrections and can't figure out this homework question??
Question 1
You can ride a taxi and pay a flat rate of $25 to go anywhere in the city, or you can pay a
base rate of $15 and $1 per mile. For which trip would it make more sense to pay the base
rate and 1$ per mile?
15 mile trip
9 mile trip
25 mile trip
O 12 mile trip
Answer:
9 mile trip
Step-by-step explanation:
$15 + $15 = $30
$15 + $9 = $24
$15 + $25 = $40
$15 + $12 = $27
$30 > $25
$24 < $25
$40 > $25
$27 > $25
which one doesn't belong ? please help thx :)
Answer:
THE CURVED ONE
Step-by-step explanation:
THE OTHER ONES R STRAIGHT LINES
THE ONE ON THE TOP RIGHT CORNER IS A PARABOLA
HOPE I HELPED
PLS MARK BRAINLIEST
DESPERATELY TRYING TO LEVEL UP
✌ -ZYLYNN JADE ARDENNE
When Sam simplified the expression 3.5 - (-4.1), she got -0.6.
What mistake did Sam likely make when she simplified
the expression?
Answer:
She forgot to combine the 2 negative signs and turn it into a positive.
Step-by-step explanation:
When you subtract a negative, you are adding the number. So if we have 3.5 - (-4.1), it would equal 3.5 + 4.1, which is 7.6
Answer:
She subtracted a negative incorrectly by simply subtracting a positive when subtracting a negative means to add a positive.
Step-by-step explanation:
She subtracted 3.5 - 4.1 which is -0.6
The problem is subtracting -4.1 which means to add 4.1
3.5 - (-4.1) = 3.5 + 4.1 = 7.6
She did: 3.5 - (-4.1) = 3.5 - 4.1 = -0.6 which is incorrect.
A kite 100 ft above the ground moves horizontally at a speed of 6 ft/s. At what rate is the angle (in radians) between the string and the horizontal decreasing when 200 ft of string have been let out? rad/s g
Answer:
0.015 radians per second.
Step-by-step explanation:
They tell us that at the moment the speed would be 6 ft / s, that is, dx / dt = 6 and those who ask us is dθ / dt.
Which we can calculate in the following way:
θ = arc sin 100/200 = pi / 6
Then we have the following equation of the attached image:
x / 100 = cot θ
we derive and we are left:
(1/100) * dx / dt = - (csc ^ 2) * θ * dθ / dt
dθ / dt = 0.01 * dx / dt / (- csc ^ 2 θ)
dθ / dt = 0.01 * 6 / (- csc ^ 2 pi / 6)
dθ / dt = 0.06 / (-2) ^ 2
dθ / dt = -0.015
So there is a decreasing at 0.015 radians per second.
The horizontal distance and the height of the kite are illustration of rates.
The angle is decreasing at a rate of 0.24 radian per second
The given parameters are:
[tex]\mathbf{Height =y= 100ft}[/tex]
[tex]\mathbf{Speed =\frac{dx}{dt}= 6fts^{-1}}[/tex]
[tex]\mathbf{Length = 200}[/tex]
See attachment for illustration
Calculate the angle using the following sine ratio
[tex]\mathbf{sin(\theta) = \frac{100}{200}}[/tex]
[tex]\mathbf{sin(\theta) = \frac{1}{2}}[/tex]
The horizontal displacement (x) is calculated using the following tangent ratio:
[tex]\mathbf{tan(\theta) = \frac{100}{x}}[/tex]
Take inverse of both sides
[tex]\mathbf{cot(\theta) = \frac{x}{100}}[/tex]
[tex]\mathbf{cot(\theta) = \frac{1}{100}x}[/tex]
Differentiate both sides with respect to time (t)
[tex]\mathbf{-csc^2(\theta) \cdot \frac{d\theta}{dt} = \frac{1}{100} \cdot \frac{dx}{dt}}[/tex]
Substitute known values
[tex]\mathbf{-csc^2(\theta) \cdot \frac{d\theta}{dt} = \frac{1}{100} \cdot 6}[/tex]
[tex]\mathbf{-csc^2(\theta) \cdot \frac{d\theta}{dt} = \frac{6}{100}}[/tex]
Recall that:
[tex]\mathbf{sin(\theta) = \frac{1}{2}}[/tex]
Take inverse of both sides
[tex]\mathbf{csc(\theta) = 2}[/tex]
Square both sides
[tex]\mathbf{csc^2(\theta) = 4}[/tex]
Substitute [tex]\mathbf{csc^2(\theta) = 4}[/tex] in [tex]\mathbf{-csc^2(\theta) \cdot \frac{d\theta}{dt} = \frac{6}{100}}[/tex]
[tex]\mathbf{-4 \cdot \frac{d\theta}{dt} = \frac{6}{100}}[/tex]
Divide both sides by -4
[tex]\mathbf{\frac{d\theta}{dt} = -\frac{24}{100}}[/tex]
[tex]\mathbf{\frac{d\theta}{dt} = -0.24}[/tex]
Hence, the angle is decreasing at a rate of 0.24 radian per second
Read more about rates at:
https://brainly.com/question/6672465
Don glover borrowed $14,000 for 250 days and paid $806.20 in simple interest on the loan. what annual simple interest rate did don pay on the loan?
Simple interest formula = I = PRT where I = interest, P = principal, r = interest rate and t = time.
i = 806.20, p = 14,000 t = 250 days.
Change t to be fraction of a full year: t = 250/365
Now solve for r:
806.20 = 14000 x r x 250/365
Simplify :
806.20 = r x 9589.04
Divide both sides by 9589.04:
r = 806.20 / 9589.04
r = 0.08407
Multiply by 100 to get percent:
r = 8.41% (rounded to nearest hundredth)
Find the product of: 1.(6a²+2b³) and -4ab²
Answer:
[tex]-24a^3b^2 -8ab^5\\[/tex]
Step-by-step explanation:
Given the two expression (6a²+2b³) and -4ab², to find their product, the following steps are valid;
[tex]= (6a^2+2b^3) *-4ab^2\\= (6a^2+2b^3)(-4ab^2)\\= (6a^2)(-4ab^2)+(2b^3)(-4ab^2) \\= -24a^3b^2 + (-8ab^5)\\= -24a^3b^2 -8ab^5\\[/tex]
The final expression gives the required product
What multiplication expression is equal to 3/5÷1/4 out of 3/5×1/4 or 5/3×1/4 or 3/5×1/4 or 3/5×4/1
Answer:
it would be 3/5*4/1
Step-by-step explanation:
To divide you multiply the first number by the reciprocal of the second number. Check and you'll see that the answer is the same. Hope this helps!
Answer:
The answer is 3/5 x 4/1
Step-by-step explanation:
what are the multiples of 5,6,8,9?
Write one to two paragraphs about what you have learned from this process. When you read, see, or hear a statistic in the future, what skills will you apply to know whether you can trust the result?
Answer:
The answer is below
Step-by-step explanation:
What must be applied to know if the result is true or reliable is a test statistic, since due to it we can calculate how true or rather what is the probability that this data will occur. There are many types of test statistic, use the one that best fits the data.
The veracity of the medium where the information comes from is also important, whether they took a representative sample or not, among other parameters.
co
Which graph represents the inequality?
-2
1-1
-12
1
1 2
NE
1
Y>-
2
2
А
++
1 -1
-12
ou
-2
od
1
NIE
1
B
1 2
2
2
---
Oto
-2
-1
1 2
-12
-
NIE
NI
12
D
-2
1 - 1
1
0
1
1 2
NIS
2
NI
Answer:
A
Step-by-step explanation:
Given the equality y > -½, it means the values of y is greater than -½.
The values of y would range from 0 upwards. I.e. 0, ½, 1, 1½, 2. . .
Thus, when graphed on a number line, the circle that appears like "o" would start from -½, and the "o" would not be full or shaded to indicate that -½ is not included in the values of y, which are greater than -½. Since the values of y are greater than -½ the direction of the arrow that indicates values of y would point towards our far right, to indicate the values included as y.
Therefore, the graph that indicates the inequality y > ½ is A
Answer:
A
Step-by-step explanation:
Is the area of this shape approximately 57 6 cm ? If not, give the correct area.
O True
O False
Answer: True
Step-by-step explanation: Taking the triangle from the left and moving it to the right creates a rectangle. From there just do 12.8×4.5.
1. A fruitseller bought 200 apples for Rs 300.40 of them were rotten and thrown away.
She sold the rest at Rs 2.25 each. Find its gain or loss percent.
253
A Book of Mathematics-8
Answer:
ok I am tellin6 to you
Step-by-step explanation:
ok I will tell to you
Write the fraction in simplest form. (3/6) x (7/10)
What pages will be favored for the given search? Search terms: Michael OR Jordan A. Pages about Michael Jordan B. Pages about Michael, plus pages about OR, plus pages about Jordan C. Pages about Michael, plus pages about Jordan D. Pages about Michael, plus pages about Jordan, plus pages about both
Answer:
A. Pages about Michael Jordan.
Step-by-step explanation:
Michael Jordan, MJ, is a great basketball player, and has achieved one the best records in his career. He is a National Basketball Association (NBA) player with great skills and energy.
From the search item, the two names Michael OR Jordan is for one person, Michael Jordan. The search would combine the two names because it is a well known one and give an output on Michael Jordan. Thus, the pages that would be favored are pages about Michael Jordan.
What is the value of this expression when n approaches infinity?
Answer:
C. Approaches 35
Step-by-step explanation:
If we graph the expression, we see that we have an asymptote at y = 35.
Check that your solutions to part (a) and (b) are consistent by substituting the expression for y into your solution for part (a).
9x^2 - y^2 = 1
Answer:
Step-by-step explanation:
The question is incomplete. Find the complete question in the attached file.
a) Given the expression 9x^2 - y^2 = 1
Differentiating implicitly will give;
[tex]18x-2y\frac{dy}{dx} = 0\\[/tex]
We can then make dy/dx the subject of the formula as shown;
[tex]18x = 2y\frac{dy}{dx}\\\frac{dy}{dx} = \frac{18x}{2y} \\\frac{dy}{dx} = \frac{9x}{y} \\y' = \frac{9x}{y}[/tex]
b) In order to solve the question explicitly, we will first have to make x the subject of the formula before differentiating.
[tex]9x^{2} -y^{2} = 1\\9x^{2} = 1+ y^{2}\\y^{2} =9x^{2}- 1\\y^{2} = 9x^{2} - 1\\y = \sqrt{9x^{2}- 1 } \\[/tex]
Using chain rule to solve the equation;
let;
[tex]u = 9x^{2} -1\\ y = u^{1/2}[/tex]
du/dx = 18x
dy/du = [tex]1/2u^{-1/2}[/tex]
dy/dx = dy/du * du/dx
dy/dx = [tex]1/2u^{-1/2} * 18x[/tex]
[tex]\frac{dy}{dx} = \frac{1}{2}({9x^{2}-1 } )^{-1/2} * 18x\\\frac{dy}{dx} = 9x({9x^{2} -1 } )^{-1/2} \\\frac{dy}{dx} = 9 x(\sqrt{{\frac{1}{9x^{2} -1} } }) \\\frac{dy}{dx} = \frac{9x}{\sqrt{9x^{2}-1 } }[/tex]
c) In order to confrim that solutions to part (a) and (b) are consistent, we will substitute [tex]y = \sqrt{9x^{2} - 1 } \\[/tex] into the answer in (a) as shown;
From (a) [tex]\frac{dy}{dx} = \frac{9x}{y} \\[/tex]
[tex]y' = \frac{9x}{ \sqrt{9x^{2} - 1 } \\} } \\}[/tex]
This shows that they are consistent
What are the y-intercepts for each function? What do these y-intercepts represent?
Answer:
In a function that is represented by Y=mx+b b would be the y-intercept
Definition of y-intercept. : the y-coordinate of a point where a line, curve, or surface intersects the y-axis.
In a family, the probability that a child is female is 0.6. if there are thee children in the family, what is the probability that 1. Exactly 2 are girls 2. At least 1 is a boy
Answer:1.P(exactly 2 kids are girls)=3/8
2. P(at least 1 is boy)=7/8
Step-by-step explanation:
1.P(exactly 2 kids are girls)=N(outcomes with 2 girls) /Total number of outcomes.
All possible outcomes are ggb,gbg, bgg, gbb, bgb, bbg, ggg, bbb - total 8
Outcomes where are exactly 2 girls are:
ggb,gbg, bgg - total 3 outcomes
So P(exactly 2 are girls)=3/8
2. P(at least 1 is boy)=Number of outcomes , where are at least 1 boy (1,2 or all 3 kids are boys)/ Total number of outcomes
All possible outcomes are ggb,gbg, bgg, gbb, bgb, bbg, ggg, bbb - total 8
Outcomes, where at least 1 kid is boy: ggb,gbg, bgg, gbb, bgb, bbg, bbb - total 7
P(at least 1 is boy)=7/8
Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use your finding to state whether or not the given r represents a significant linear correlation. Use a significance level of 0.05. r=0.767, n=25 A. Critical values: r= +0.396, no significant linear correlation B. Critical values: r= +0.487, no significant linear correlation C. Critical values: r = +0.396, significant linear correlation D. Critical values: r = + 0.487, significant linear correlation
Answer:
C. Critical values: r = +0.396
Step-by-step explanation:
Hello!
A linear correlation for two variables X₁ and X₂ was calculated.
For a sample n= 25 the sample correlation coefficient is r= 0.767.
Be the hypotheses:
H₀: ρ = 0
H₁: ρ ≠ 0
α: 0.05
For this hypothesis test, the rejection region is two-tailed, and the degrees of freedom are Df= n-2= 25-2= 23
So using the Pearson product-moment correlation coefficient table of critical values, under the entry for "two tailed tests" you have to cross the level of significance and the degrees of freedom to find the corresponding critical value:
[tex]r_{n-2;\alpha }= r_{23;0.05}= 0.396[/tex]
Since the calculated correlation coefficient is greater than the critical value, you can reject the null hypothesis, this means that the correlation is significant at level 5%
I hope this helps!
Write 17857000012 in words
Answer:
Seventeen billion, eight hundred fifty-seven million and twelve.
Step-by-step explanation:
Answer:
17,857,000,012 = 17 billion 857 million 12
Step-by-step explanation:
Bye lad!
Find the percent of increase. Original Price: $135 Retail Price: $162
20%
Here's a tip: Always start percentage calculating with dividing the current number by 10.
Please answer this correctly
Answer:
Option 2
Step-by-step explanation:
The average temperature in January is -1 degrees celsius. Last year, it was 1 degrees celsius higher than the average.
-1 + 1 = 0
Answer:
The second answer.
Step-by-step explanation:
The average temp. is -1C.
'was 1C warmer' = +1
-1+1=0
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What is your question?
Answer:
yeah what's your question?
The scheduled arrival time for a daily flight from Boston to New York is 9:30 am. Historical data show that the arrival time follows the continuous uniform distribution with an early arrival time of 9:07 am and a late arrival time of 9:57 am.a. After converting the time data to a minute scale, calculate the mean and the standard deviation for the distribution. (Round your answers to 2 decimal places.)Mean:____________________________ minutes Standard deviation: _________________ minutes b. What is the probability that a flight arrives late (later than 9:30 am)? (Do not round intermediate calculations. Round your answer to 2 decimal places.)Probability:________
Answer:
Step-by-step explanation:
Let x be a random variable representing the flight arrival time from Boston to New York.
For a uniform probability distribution, the notation is
X U(a, b) where a is the lowest value of x and b is the lowest value of x
The probability density function, f(x) = 1/(b - a)
Mean, µ = (a + b)/2
Standard deviation, σ = √(b - a)²/12
From the information given, the time difference in minutes is 9:57 - 9:07 = 50 minutes. Therefore,
a = 0
b = 50
µ = (0 + 50)/2 = 25
σ = √(50 - 0)²/12 = 14.43
b) converting to minutes, it is 9:30 - 9:07 = 23 minutes
the probability that a flight arrives late(later than 9:30 am) is expressed as P(x > 23)
f(x) = 1/(50) = 0.02
P(x > 23) = (50 - 23)0.02 = 0.54