Answer:
196 ft^2
Step-by-step explanation:
4(w) = L
2w + 2L = 70
2w + 2(4w) = 70
10w = 70
w = 7
4(7) = 28
Area = 28*7
Area = 196
Answer:
The area of the rectangle is 196 ft^2.
Step-by-step explanation:
Looking for: Area
The length of a rectangle is four times its width can be translated into
l = 4w
Perimeter = 2w + 2l
2w + 2(4w) = 70
2w + 8w = 70
10w = 70
w = 7
l = 4w
l= 4(7)
l=28
Area = l times w
28 times 7 = 196
The area of the rectangle is 196 ft^2.
The probability distribution for a
random variable x is given in the table.
Answer: 79% probability
Step-by-step explanation:
.17 + .13 + .33 + .16 = .79
.79 x 100 = 79%
Answer:
.79
Step-by-step explanation:
Unit sales for new product ABC has varied in the first seven months of this year as follows: Month Jan Feb Mar Apr May Jun Jul Unit Sales 330 274 492 371 160 283 164 What is the (population) standard deviation of the data
Answer:
Approximately standard deviation= 108
Step-by-step explanation:
Let's calculate the mean of the data first.
Mean =( 330+ 274+ 492 +371 +160+ 283+ 164)/7
Mean= 2074/7
Mean= 296.3
Calculating the variance.
Variance = ((330-296.3)²+( 274-296.3)²+ (492-296.3)²+( 371-296.3)²+ (160-296.3)² (283-296.3)²+(164-296.3)²)/7
Variance= (1135.69+497.29+38298.49+5580.09+18577.69+176.89+17503.29)/7
Variance= 81769.43/7
Variance= 11681.347
Standard deviation= √variance
Standard deviation= √11681.347
Standard deviation= 108.080
Approximately 108
A publisher reports that 45% of their readers own a laptop. A marketing executive wants to test the claim that the percentage is actually different from the reported percentage. A random sample of 370 found that 40% of the readers owned a laptop. Is there sufficient evidence at the 0.02 level to support the executive's claim?
Answer:
At a significance level of 0.02, there is not enough evidence to support the claim that the percentage of readers that own a laptop is significantly different from 45%.
P-value = 0.06
Step-by-step explanation:
This is a hypothesis test for a proportion.
The claim is that the percentage of readers that own a laptop is significantly different from 45%.
Then, the null and alternative hypothesis are:
[tex]H_0: \pi=0.45\\\\H_a:\pi\neq 0.45[/tex]
The significance level is 0.02.
The sample has a size n=370.
The sample proportion is p=0.4.
The standard error of the proportion is:
[tex]\sigma_p=\sqrt{\dfrac{\pi(1-\pi)}{n}}=\sqrt{\dfrac{0.45*0.55}{370}}\\\\\\ \sigma_p=\sqrt{0.000669}=0.026[/tex]
Then, we can calculate the z-statistic as:
[tex]z=\dfrac{p-\pi+0.5/n}{\sigma_p}=\dfrac{0.4-0.45+0.5/370}{0.026}=\dfrac{-0.049}{0.026}=-1.881[/tex]
This test is a two-tailed test, so the P-value for this test is calculated as:
[tex]\text{P-value}=2\cdot P(z<-1.881)=0.06[/tex]
As the P-value (0.06) is greater than the significance level (0.02), the effect is not significant.
The null hypothesis failed to be rejected.
At a significance level of 0.02, there is not enough evidence to support the claim that the percentage of readers that own a laptop is significantly different from 45%.
A bacteria culture initially contains 100 cells and grows at a rate proportional to its size. After an hour the population has increased to 420. Find the rate of growth after 3 hours.
Step-by-step explanation:
Rate of growth equals 420/100 = 4.2 times per hour
So after t=three hours,
size of culture = 100*(4.2)^t = 100*4.2^3=7408.8 bacteria,
round to nearest unit 7409 bacteria after three hours (after initial size of 100).
Answer:
a) 100•4.2^t
b) P(3)= about 7409 bacteria
c) P’(3)= about 10,632 bacteria per hour
d) t= about 3.2 hours
Step-by-step explanation:
Find the total surface area of this triangular prism 13cm 5cm 12cm 9cm 15cm 20cm
Answer:
924 cm²
Step-by-step explanation:
The surface area is equal to the area of the two triangles + area of the three rectangles.
Area of two triangles:
12 × (9+5) × 1/2
= 84
84(2) = 168
Area of the three rectangles:
15 × 20 + 13 × 20 + 14 × 20
= 840
840 + 84
The surface area of the triangular prism is 924 cm².
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Answer:
that's cool . . .
\is ok everyone makes mistakes
If the area of a circular cookie is 28.26 square inches, what is the APPROXIMATE circumference of the cookie? Use 3.14 for π.
75.2 in.
56.4 in.
37.6 in.
18.8 in.
Answer:
Step-by-step explanation:
c= 2(pi)r
Area = (pi)r^2
28.26 = (pi) r^2
r =[tex]\sqrt{9}[/tex] = 3
circumference = 2 (3.14) (3)
= 18.8 in
Answer: approx 18.8 in
Step-by-step explanation:
The area of the circle is
S=π*R² (1) and the circumference of the circle is C= 2*π*R (2)
So using (1) R²=S/π=28.26/3.14=9
=> R= sqrt(9)
R=3 in
So using (2) calculate C=2*3.14*3=18.84 in or approx 18.8 in
What number : Decreased by 40% is 60 ?
Answer:
100
Step-by-step explanation:
The number, when decreased by 40%, is equal to 100.
What is the percentage?
The Percentage is defined as representing any number with respect to 100. It is denoted by the sign %.
Let the number be x then the number is calculated as:-We can see that the number is decreased by 40% then the remaining part is 60%
x ( 60% ) = 60
x ( 60 / 100 ) = 60
x = 100
Hence, the number, when decreased by 40%, is equal to 100.
To know more about percentages follow
https://brainly.com/question/24304697
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What is the equation of a line passes thru the point (4, 2) and is perpendicular to the line whose equation is y = ×/3 - 1 ??
Answer:
Perpendicular lines have slopes that are opposite and reciprocal. Therefore, the line we are looking for has a -3 slope.
y= -3x+b
Now, we can substitute in the point given to find the intercept.
2= -3(4)+b
2= -12+b
b=14
Finally, put in everything we've found to finish the equation.
y= -3x+14
Answer:
y = -3x + 14
Step-by-step explanation:
First find the reciprocal slope since it is perpendicular. Slope of the other line is 1/3 so the slope for our new equation is -3.
Plug information into point-slope equation
(y - y1) = m (x-x1)
y - 2 = -3 (x-4)
Simplify if needed
y - 2 = -3x + 12
y = -3x + 14
Factor the polynomial expression x4 – 6x2 + 5.
Answer:
Hello!
______________________
x4 – 6x2 + 5
= ( x^2 - 5) ( x + 1 ) ( x - 1 )
Step-by-step explanation: Factor.
Hope this helped you!
The point StartRoot x EndRoot is plotted on the number line. A number line going from 9 to 10 in increments of 0.1. StartRoot x EndRoot is plotted between 9.3 and 9.4. What whole number best approximates the value of x? 81 87 88 93
Answer:
87
Step-by-step explanation:
Prove that If A1, A2, ... , An and B1, B2,...,Bn are sets such that Aj ⊆ Bj for j = 1, 2, 3, ... , n, then ∪j=1nAj ⊆ ∪j=1nBj .
Answer:
This is proved using Proof by induction method. There are two steps in this method
Let P(n) represent the given statement ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex]
1. Basis Step: This step proves the given statement for n = 1
2. Induction step: The step proves that if the given statement holds for any given case n = k then it should also be true for n = k + 1.
If the above two steps are true this means that given statement P(n) holds true for all positive n and the mathematical induction P(n): ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] is true.
Step-by-step explanation:
Basis Step:
For n = 1
∪[tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] = ∪[tex]{ {{1} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] = A₁ ⊆ B₁ = ∪[tex]{ {{1} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] = ∪[tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex]
We show that
∪[tex]{ {{1} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] = A₁ ⊆ B₁ = ∪[tex]{ {{1} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] for n = 1
Hence P(1) is true
Induction Step:
Let P(k) be true which means that we assume that:
for all k with k≥1, P(k): ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] is true
This is our induction hypothesis and we have to prove that P(k + 1) is also true
This means if ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] holds for n = k then this should also hold for n = k + 1.
In simple words if P(k): ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] is true then ∪[tex]{ {{k+1} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪[tex]{ {{k+1} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] is also true
∪[tex]{ {{k+1} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] = ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ∪ [tex]A_{k+1}[/tex]
⊆ ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] ∪ [tex]A_{k+1}[/tex] As ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex]
⊆ ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] ∪ [tex]B_{k+1}[/tex] As [tex]A_{k+1}[/tex] ⊆ [tex]B_{k+1}[/tex]
= ∪[tex]{ {{k+1} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex]
The whole step:
∪[tex]{ {{k+1} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] = ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ∪ [tex]A_{k+1}[/tex] ⊆ ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] ∪ [tex]A_{k+1}[/tex] ⊆ ∪[tex]{ {{k} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] ∪ [tex]B_{k+1}[/tex] = ∪[tex]{ {{k+1} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex]
shows that the P(k+1) also holds for ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex]
hence P(k+1) is true
So proof by induction method proves that P(n) is true. This means
P(n): ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]A_{j}[/tex] ⊆ ∪ [tex]{ {{n} \atop {j=1}} \right.[/tex] [tex]B_{j}[/tex] is true
Over the past several years, the proportion of one-person households has been increasing. The Census Bureau would like to test the hypothesis that the proportion of one-person households exceeds 0.27. A random sample of 125 households found that 43 consisted of one person. The Census Bureau would like to set α = 0.05. Use the critical value approach to test this hypothesis. Explain.
Answer:
For this case we can find the critical value with the significance level [tex]\alpha=0.05[/tex] and if we find in the right tail of the z distribution we got:
[tex] z_{\alpha}= 1.64[/tex]
The statistic is given by:
[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)
Replacing we got:
[tex]z=\frac{0.344 -0.27}{\sqrt{\frac{0.27(1-0.27)}{125}}}=1.86[/tex]
Since the calculated value is higher than the critical value we have enough evidence to reject the null hypothesis and we can conclude that the true proportion of households with one person is significantly higher than 0.27
Step-by-step explanation:
We have the following dataset given:
[tex] X= 43[/tex] represent the households consisted of one person
[tex]n= 125[/tex] represent the sample size
[tex] \hat p= \frac{43}{125}= 0.344[/tex] estimated proportion of households consisted of one person
We want to test the following hypothesis:
Null hypothesis: [tex]p \leq 0.27[/tex]
Alternative hypothesis: [tex]p>0.27[/tex]
And for this case we can find the critical value with the significance level [tex]\alpha=0.05[/tex] and if we find in the right tail of the z distribution we got:
[tex] z_{\alpha}= 1.64[/tex]
The statistic is given by:
[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)
Replacing we got:
[tex]z=\frac{0.344 -0.27}{\sqrt{\frac{0.27(1-0.27)}{125}}}=1.86[/tex]
Since the calculated value is higher than the critical value we have enough evidence to reject the null hypothesis and we can conclude that the true proportion of households with one person is significantly higher than 0.27
The following confidence interval for the population proportion for how many U.S. adults do not get enough fruits and vegetables in their diet is constructed at what level of confidence, if there were 2050 people in the survey? (0.878,0.903)
Answer:
The interval is constructed at 93% confidence.
Step-by-step explanation:
Confidence interval concepts:
A confidence interval has two bounds, a lower bound and an upper bound.
A confidence interval is symmetric, which means that the point estimate used is the mid point between these two bounds, that is, the mean of the two bounds.
The margin of error is the difference between these two bounds, divided by 2.
Confidence interval of proportions concepts:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In this problem, we have that:
2050 people, so n = 2050.
Lower bound: 0.878
Upper bound: 0.903
[tex]\pi = \frac{0.878 + 0.903}{2} = 0.8905[/tex]
[tex]M = \frac{0.903 - 0.878}{2} = 0.0125[/tex]
Confidence level:
We have to find z.
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.0125 = z\sqrt{\frac{0.8905*0.1095}{2050}}[/tex]
[tex]0.0069z = 0.0125[/tex]
[tex]z = \frac{0.0125}{0.0069}[/tex]
[tex]z = 1.81[/tex]
[tex]z = 1.81[/tex] has a pvalue of 0.965.
That is:
[tex]]1 - \frac{\alpha}{2} = 0.965[/tex]
[tex]\frac{\alpha}{2} = 0.035[/tex]
[tex]\alpha = 2*0.035[/tex]
[tex]\alpha = 0.07[/tex]
Finally
[tex]1 - \alpha = 1 - 0.07 = 0.93[/tex]
The interval is constructed at 93% confidence.
Will give brainliest answer
Answer:
98 unitsSolution,
Circumference of circle = 615.44 units
Radius = ?
Now,
Circumference of circle = 615.44
[tex]2\pi \: r = 615.44[/tex]
[tex]2 \times 3.14 \times r = 615.44[/tex]
[tex]6.28r = 615.44[/tex]
[tex]r = \frac{615.44}{6.28} [/tex]
[tex]r = 98 \: units[/tex]
Hope this helps...
Good luck on your assignment...
In 4 days, the price of a share of stock rose 3/4 of a point. On a average, what was the change in stock each day? Answers: A) 3 Points B) 3/16 Points C) 1 3/4 Points D) 1/3 Points
Answer:
i think the answer is option 1 3
Step-by-step explanation:
i say this bc 3/4 times 4 is 3
hope this helps
if this is the correct answer plz mark brainliest.
2-x=-3(x+4)+6 please help
Answer:
2-x=-3x-12+6
2-x=-3x-6
8=-3x+x
8=-2x
x=-4
hope it's clear
mark me as brainliest
Answer:
X = -4Option B is the correct option.
Step by step explanation
2 - x = -3 ( x + 4) +6
Distribute -3 through the paranthesis
2 - x = - 3x - 12 + 6
Calculate
2 - x = - 3x - 6
Move variable to LHS and change its sign
2 - x + 3x = -6
Move constant to R.H.S and change its sign
- x + 3x = -6 - 2
Collect like terms and simplify
2x = -8
Divide both side by 2
2x/2 = -8/2
Calculate
X = -4
Hope this helps....
Good luck on your assignment..
Determine the point estimate of the population proportion, the margin of error for the following confidence interval, and the number of individuals in the sample with the specified characteristic, x, for the sample size provided. Lower boundequals0.645, upper boundequals0.915, nequals1500
Answer:
The point estimate of the population proportion is 0.78.
The margin of error of the interval is of 0.135 = 13.5%.
The number of individuals in the sample with the specified characteristic is 1170.
Step-by-step explanation:
Confidence interval concepts:
A confidence interval has two bounds, a lower bound and an upper bound.
A confidence interval is symmetric, which means that the point estimate used is the mid point between these two bounds, that is, the mean of the two bounds.
The margin of error is the subtraction of these two bounds divided by 2.
In this question:
Lower bound: 0.645
Upper bound: 0.915
Point estimate of the population proportion
[tex]p = \frac{0.645 + 0.915}{2} = 0.78[/tex]
The point estimate of the population proportion is 0.78
Margin of error for the following confidence interval
[tex]M = \frac{0.915 - 0.645}{2} = 0.135[/tex]
The margin of error of the interval is of 0.135 = 13.5%.
The number of individuals in the sample with the specified characteristic
78% of 1500
0.78*1500 = 1170
The number of individuals in the sample with the specified characteristic is 1170.
What are the steps and answer to this equation?[tex](8x^4)/(16x^7)[/tex]
Answer:
[tex] \frac{1}{2 {x}^{3} } [/tex]Step-by-step explanation:
[tex] \frac{8 {x}^{4} }{16 {x}^{7} } [/tex]
Reduce the fraction with 8
[tex] \frac{ {x}^{4} }{2 {x}^{7} } [/tex]
Simplify the expression
[tex] \frac{1}{2 {x}^{3} } [/tex]
Hope this helps...
Good luck on your assignment...
. If α and β are the roots of
2x^2+7x-9=0 then find the equation whose roots are
α/β ,β/α
Answer:
[tex]18x^2+85x+18 = 0[/tex]
Step-by-step explanation:
Given Equation is
=> [tex]2x^2+7x-9=0[/tex]
Comparing it with [tex]ax^2+bx+c = 0[/tex], we get
=> a = 2, b = 7 and c = -9
So,
Sum of roots = α+β = [tex]-\frac{b}{a}[/tex]
α+β = -7/2
Product of roots = αβ = c/a
αβ = -9/2
Now, Finding the equation whose roots are:
α/β ,β/α
Sum of Roots = [tex]\frac{\alpha }{\beta } + \frac{\beta }{\alpha }[/tex]
Sum of Roots = [tex]\frac{\alpha^2+\beta^2 }{\alpha \beta }[/tex]
Sum of Roots = [tex]\frac{(\alpha+\beta )^2-2\alpha\beta }{\alpha\beta }[/tex]
Sum of roots = [tex](\frac{-7}{2} )^2-2(\frac{-9}{2} ) / \frac{-9}{2}[/tex]
Sum of roots = [tex]\frac{49}{4} + 9 /\frac{-9}{2}[/tex]
Sum of Roots = [tex]\frac{49+36}{4} / \frac{-9}{2}[/tex]
Sum of roots = [tex]\frac{85}{4} * \frac{2}{-9}[/tex]
Sum of roots = S = [tex]-\frac{85}{18}[/tex]
Product of Roots = [tex]\frac{\alpha }{\beta } \frac{\beta }{\alpha }[/tex]
Product of Roots = P = 1
The Quadratic Equation is:
=> [tex]x^2-Sx+P = 0[/tex]
=> [tex]x^2 - (-\frac{85}{18} )x+1 = 0[/tex]
=> [tex]x^2 + \frac{85}{18}x + 1 = 0[/tex]
=> [tex]18x^2+85x+18 = 0[/tex]
This is the required quadratic equation.
Answer:
α/β= -2/9 β/α=-4.5
Step-by-step explanation:
So we have quadratic equation 2x^2+7x-9=0
Lets fin the roots using the equation's discriminant:
D=b^2-4*a*c
a=2 (coef at x^2) b=7(coef at x) c=-9
D= 49+4*2*9=121
sqrt(D)=11
So x1= (-b+sqrt(D))/(2*a)
x1=(-7+11)/4=1 so α=1
x2=(-7-11)/4=-4.5 so β=-4.5
=>α/β= -2/9 => β/α=-4.5
Can somebody help me i have to drag the functions on top onto the bottom ones to match their inverse functions.
Answer:
1. x/5
2. cubed root of 2x
3.x-10
4.(2x/3)-17
Step-by-step explanation:
Answer:
Step-by-step explanation:
1. Lets find the inverse function for function f(x)=2*x/3-17
To do that first express x through f(x):
2*x/3= f(x)+17
2*x=(f(x)+17)*3
x=(f(x)+17)*3/2 done !!! (1)
Next : to get the inverse function from (1) substitute x by f'(x) and f(x) by x.
So the required function is f'(x)=(x+17)*3/2 or f'(x)=3*(x+17)/2
This is function is No4 in our list. So f(x)=2*x/3-17 should be moved to the box No4 ( on the bottom) of the list.
2. Lets find the inverse function for function f(x)=x-10
To do that first express x through f(x):
x= f(x)+10
x=f(x)+10 done !!! (2)
Next : to get the inverse function from (2) substitute x by f'(x) and f(x) by x.
So the required function is f'(x)=x+10
This is function is No3 in our list. So f(x)=x-10 should be moved to the box No3 ( from the top) of the list.
3.Lets find the inverse function for function f(x)=sqrt 3 (2x)
To do that first express x through f(x):
2*x= f(x)^3
x=f(x)^3/2 done !!! (3)
Next : to get the inverse function from (3) substitute x by f'(x) and f(x) by x.
So the required function is f'(x)=x^3/2
This is function No2 in our list. So f(x)=sqrt 3 (2x) should be moved to the box No2 ( from the top) of the list.
4.Lets find the inverse function for function f(x)=x/5
To do that first express x through f(x):
x=f(x)*5 done !!! (4)
Next : to get the inverse function from (4) substitute x by f'(x) and f(x) by x.
So the required function is f'(x)=x*5 or f'(x)=5*x
This is function No1 in our list. So f(x)=x/5 should be moved to the box No1 ( on the top) of the list.
Suppose μ1 and μ2 are true mean stopping distances at 50 mph for cars of a certain type equipped with two different types of braking systems. Use the two-sample t test at significance level 0.01 to test H0: μ1 − μ2 = −10 versus Ha: μ1 − μ2 < −10 for the following data: m = 8, x = 115.6, s1 = 5.04, n = 8, y = 129.3, and s2 = 5.32.
Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.)
t = ________
P-value = _________
Answer:
Step-by-step explanation:
This is a test of 2 independent groups. Given that μ1 and μ2 are true mean stopping distances at 50 mph for cars of a certain type equipped with two different types of braking systems, the hypothesis are
For null,
H0: μ1 − μ2 = - 10
For alternative,
Ha: μ1 − μ2 < - 10
This is a left tailed test.
Since sample standard deviation is known, we would determine the test statistic by using the t test. The formula is
(x1 - x2)/√(s1²/n1 + s2²/n2)
From the information given,
x1 = 115.6
x2 = 129.3
s1 = 5.04
s2 = 5.32
n1 = 8
n2 = 8
t = (115.6 - 129.3)/√(5.04²/8 + 5.32²/8)
t = - 2.041
Test statistic = - 2.04
The formula for determining the degree of freedom is
df = [s1²/n1 + s2²/n2]²/(1/n1 - 1)(s1²/n1)² + (1/n2 - 1)(s2²/n2)²
df = [5.04²/8 + 5.32²/8]²/[(1/8 - 1)(5.04²/8)² + (1/8 - 1)(5.32²/8)²] = 45.064369/3.22827484
df = 14
We would determine the probability value from the t test calculator. It becomes
p value = 0.030
Since alpha, 0.01 < the p value, 0.03, then we would fail to reject the null hypothesis.
Find the length of a picture frame whose width is 3 inches and whose proportions are the same as a 9-inch wide by 12-inch long picture frame.
Answer:
4 inches
Step-by-step explanation:
We can set up a proportion to find out the length value (assuming x is the length of the frame)
[tex]\frac{3}{x} = \frac{9}{12}[/tex]
We multiply 12 and 3...
[tex]12\cdot3=36[/tex]
And divide by 9...
[tex]36\div9=4[/tex]
So, the length of the frame is 4 inches.
Hope this helped!
Answer:
Step-by-step explanation:
4 inches
please help i will give out brainliest
Answer:
answer C
Step-by-step explanation:
because the plan view of a solid 3-D figure is the view from the top which would be 3 squares in a row which is exactly what is shown in answer C.
Answer:
D
Step-by-step explanation:
D is the answer because every part of the cube is formed from 2 horizontal cubes
Two roots of a 3-degree polynomial equation are 5 and -5. Which of the following cannot be the third root of the equation? 0 -5i -5 5i 5
Answer:
-5i and 5i cannot be roots of the equation, since they are complex.
Step-by-step explanation:
A 3-degree polynomial equation must have 3 roots, if one of its roots is a complex number, then its conjugate must also be a root of the function. The problem already stated two roots, which are reals, therefore the last root must also be real. Using this line of thought we know that -5i and 5i cannot be roots of the equation, since they're complex.
Use the Remainder Theorem to determine which of the roots are roots of F(x). Show your work.
Polynomial: F(x)=x^3-x^2-4x+4
Roots: 1, -2, and 2.
Answer: x1=1 x2=-2 and x3=2
Step-by-step explanation:
1st x1=1 is 1 of the roots , so
F(1)=1-1-4+4=0 - true
So lets divide x^3-x^2-4x+4 by (x-x1), i.e (x^3-x^2-4x+4) /(x-1)=(x^2-4)
x^2-4 can be factorized as (x-2)*(x+2)
So x^3-x^2-4x+4=(x-1)*(x^2-4)=(x-1)(x-2)*(x+2)
So there are 3 dofferent roots:
x1=1 x2=-2 and x3=2
A group of 20 people were asked to remember as many items as possible from a list before and after being taught a memory device. Researchers want to see if there is a significant difference in the amount of items that people are able to remember before and after being taught the memory device. They also want to determine whether or not men and women perform differently on the memory test. They choose α = 0.05 level to test their results. Use the provided data to run a Two-way ANOVA with replication.
A B C
Before After
Male 5 7
4 5
7 8
7 8
7 8
7 8
5 6
7 7
6 7
Female 5 8
5 6
8 8
7 7
6 6
8 9
8 8
6 6
7 6
8 8
Answer:
1. There is no difference in amount of items that people are able to remember before and after being taught the memory device.
2. There is no difference between performance of men and women on memory test.
Step-by-step explanation:
Test 1:
The hypothesis for the two-way ANOVA test can be defined as follows:
H₀: There is no difference in amount of items that people are able to remember before and after being taught the memory device.
Hₐ: There is difference in amount of items that people are able to remember before and after being taught the memory device.
Use MS-Excel to perform the two-way ANOVA text.
Go to > Data > Data Analysis > Anova: Two-way with replication
A dialog box will open.
Input Range: select all data
Rows per sample= 10
Alpha =0.05
Click OK
The ANOVA output is attaches below.
Consider the Columns data:
The p-value is 0.199.
p-value > 0.05
The null hypothesis will not be rejected.
Conclusion:
There is no difference in amount of items that people are able to remember before and after being taught the memory device.
Test 2:
The hypothesis to determine whether or not men and women perform differently on the memory test is as follows:
H₀: There is no difference between performance of men and women on memory test.
Hₐ: There is a difference between performance of men and women on memory test.
Consider the Sample data:
The p-value is 0.075.
p-value > 0.05
The null hypothesis will not be rejected.
Conclusion:
There is no difference between performance of men and women on memory test.
Identify the axis of symmetry and vertex of f(x) = –x2 –2x–1.
Answer:
Vertex: (-1, 0)
Axis of Symmetry: x = -1
Step-by-step explanation:
Use a graphing calc.
consider the difference of squares identity a^2-2b^2=(a+b)(a-b)
Answer: a= 3x and b= 7
Step-by-step explanation:
^^
Suppose a Google.com bond will pay $4,500 ten years from now. If the going interest rate on safe 10-year bonds is 4.25%, how much is the bond worth today?
Answer:
2,967.92 ( dollars )
Step-by-step explanation:
The amount the bond is worth, should be the present value of the bond, other wise known as PV. If it is given that Google.com bond will pay $ 4,500 ten years from now, it should be that the future value, otherwise known as FV, is 4,500 dollars.
Consider the given. There is a 4.25 percent discount rate, a time span of 10 years ( tenor / time ) and of course a future value of 4,500 dollars. Using this, we can calculate the present value -
[tex]PV = FV / ( ( 1 + rate )^{time} ),\\PV = 4,500 / ( 1 + 4.25 / 100 )^{10}\\----\\( Calculations ) PV = ( About ) 2,967.92 ( dollars )\\Solution = 2968 ( dollars )[/tex]
As you can see, through simple calculations the solution should be that the bond worth is about $ 2,967.92