Question 1

A researcher wanted to determine if using an octane booster would increase gasoline mileage.A random
sample of seven cars was selected; the cars were driven for two weeks without the booster and two weeks
with the booster. 
-What is the critical value using

Accepted Answer

A) -1.782 
B) -1.761 
C) -1.943 
D) -1.895

Question 2

What is the null hypothesis? Use  . Refer To: 09-18

Accepted Answer

A)   
B)   
C)   
D)

Question 3

Find  and  , if  .

Accepted Answer

The answer of Find  and  , if ...

Question 4

Joan moves into her new apartment and wants to purchase a new couch.She wants to determine if there is
any difference between the average costs of couches at two different stores.Test the hypothesis that there
is no difference at

Accepted Answer

The answer of Joan moves into her new apartment and...

Question 5

70% of students at a university live on campus.A random sample found that 35 of 50 male students and 42 of 50 of female students lived on campus.At the .05 level of significance, is there sufficient evidence
To conclude that a difference exists between the proportion of male students who live on campus and the
Proportion of female students who live on campus?

Accepted Answer

A) No, there is not sufficient information to reject the hypothesis that the proportion of male students who
Live on campus and the proportion of female students who live on campus are the same because the test
Value -0.14 is inside the acceptance region (-1.96,1.96). 
B) No, there is not sufficient information to reject the hypothesis that the proportion of male students who
Live on campus and the proportion of female students who live on campus are the same because the test
Value -0.90 is inside the acceptance region (-1.96,1.96). 
C) No, there is not sufficient information to reject the hypothesis that the proportion of male students who
Live on campus and the proportion of female students who live on campus are the same because the test
Value -1.73 is inside the acceptance region (-1.96,1.96). 
D) No, there is not sufficient information to reject the hypothesis that the proportion of male students who
Live on campus and the proportion of female students who live on campus are the same because the test
Value -1.66 is inside the acceptance region (-1.96,1.96).

Question 6

A researcher wanted to determine if using an octane booster would increase gasoline mileage.A random
sample of seven cars was selected; the cars were driven for two weeks without the booster and two weeks
with the booster. 
-Compute the standard deviation of the difference.

Accepted Answer

A) 0.78 
B) 0.69 
C) 0.87 
D) 0.48

Question 7

A study of cats and dogs found that 25 of 50 cats and 44 of 60 dogs slept more than 10 hours per day.At the .05 level of significance, is there sufficient evidence to conclude that a difference exists between the
Proportion of cats and the proportion of dogs that sleep more than 10 hours per day?

Accepted Answer

A) Yes, there is sufficient information to reject the hypothesis that the proportion of cats and the proportion
Of dogs that sleep more than 10 hours per day are the same because the test value -2.52 is outside the
Acceptance region (-1.96,1.96). 
B) No, there is not sufficient information to reject the hypothesis that the proportion of cats and the
Proportion of dogs that sleep more than 10 hours per day are the same because the test value -1.64 is
Inside the acceptance region (-1.96,1.96). 
C) Yes, there is sufficient information to reject the hypothesis that the proportion of cats and the proportion
Of dogs that sleep more than 10 hours per day are the same because the test value -2.90 is outside the
Acceptance region (-1.96,1.96). 
D) No, there is not sufficient information to reject the hypothesis that the proportion of cats and the
Proportion of dogs that sleep more than 10 hours per day are the same because the test value -0.77 is
Inside the acceptance region (-1.96,1.96).

Question 8

For the samples summarized below, test the hypothesis at  that the two variances are equal.

Accepted Answer

A) Fail to reject the hypothesis because the test value 3.00 is less than the critical value 3.01. 
B) Reject the hypothesis because the test value 3.00 is less than the critical value 3.01. 
C) Fail to reject the hypothesis because the test value 9.00 is greater than the critical value 2.88. 
D) Reject the hypothesis because the test value 9.00 is greater than the critical value 2.88.

Question 9

When finding the F -test value, the smaller of the variances is placed in the numerator.

Accepted Answer

A) True 
 B)False

Question 10

The critical value for a left-tailed t-test for dependent samples is __________ when the degrees of
freedom = 7 and

Accepted Answer

The answer of The critical value for a left-tailed t-test...

Question 11

Determine the value of  s shown in the figure below, if the degrees of freedom were 7 and 9.

Accepted Answer

A) 0.01 
B) 0.025 
C) 0.05 
D) 0.1

Question 12

What is the test value? Use  Refer To: 09-18

Accepted Answer

A) -6.86 
B) -3.70 
C) -4.13 
D) -5.45

Question 13

The value of F cannot be negative, because variances are always positive or zero.

Accepted Answer

A) True 
 B)False

Question 14

Samples are independent when they are not related.

Accepted Answer

A) True 
 B)False

Question 15

Find  when  = 15, and  = 60

Accepted Answer

A)   
B)   
C)   
D)

Question 16

Mauricio Tersignico, a local wine merchant, wants to determine if the average price of domestic wine
is less than the average price of imported wine.The data obtained is shown in the table below. 
-What is the critical value? Use  (Use the variances unequal formula.)

Accepted Answer

A) -1.761 
B) -2.045 
C) -1.697 
D) -1.703

Question 17

A running coach wanted to see whether runners ran faster after eating spaghetti the night before a race. Twenty-four random runners were chosen for this study.They ran a 5-kilometre race after having a
Normal dinner the night before, and then a week later, re-ran the same race after having a spaghetti dinner
The night before.Their results (in seconds) are in the table below.At  , what is the test value for
This test?

Accepted Answer

A) -3.41 
B) -1.00 
C) -0.26 
D) -4.90

Question 18

One poll found that 41% of male voters will support a candidate while another found that 49% of female voters will be in support.To test whether this candidate has equal levels of support between male and
Female voters, the null hypothesis should be

Accepted Answer

A)   
B)   
C)   
D)

Question 19

A recent survey reported that in a sample of 300 students who attend community colleges, 105 work at least 20 hours a week.In a sample of 225 students attending universities, only 20 students were found to
Work at least 20 hours per week.What is the test value?

Accepted Answer

A) 6.95 
B) 7.61 
C) 2.38 
D) 4.18

Question 20

Donaldson Corporation wants to hire a temporary secretary.There are two employment agencies in town,
and it is believed that the average hourly wages charged by both agencies are the same.Test this claim at

Accepted Answer

The answer of Donaldson Corporation wants to hire a temporary...

Exam 9: Testing the Difference Between Two Means, Two Variances, and Two Proportions

A researcher wanted to determine if using an octane booster would increase gasoline mileage.A random sample of seven cars was selected; the cars were driven for two weeks without the booster and two weeks with the booster. -What is the critical value using

What is the null hypothesis? Use . Refer To: 09-18

Find and , if .

Joan moves into her new apartment and wants to purchase a new couch.She wants to determine if there is any difference between the average costs of couches at two different stores.Test the hypothesis that there is no difference at

A researcher wanted to determine if using an octane booster would increase gasoline mileage.A random sample of seven cars was selected; the cars were driven for two weeks without the booster and two weeks with the booster. -Compute the standard deviation of the difference.

A study of cats and dogs found that 25 of 50 cats and 44 of 60 dogs slept more than 10 hours per day.At the .05 level of significance, is there sufficient evidence to conclude that a difference exists between the Proportion of cats and the proportion of dogs that sleep more than 10 hours per day?

For the samples summarized below, test the hypothesis at that the two variances are equal.

When finding the F -test value, the smaller of the variances is placed in the numerator.

The critical value for a left-tailed t-test for dependent samples is __________ when the degrees of freedom = 7 and

Determine the value of s shown in the figure below, if the degrees of freedom were 7 and 9.

What is the test value? Use Refer To: 09-18

The value of F cannot be negative, because variances are always positive or zero.

Samples are independent when they are not related.

Find when = 15, and = 60

Mauricio Tersignico, a local wine merchant, wants to determine if the average price of domestic wine is less than the average price of imported wine.The data obtained is shown in the table below. -What is the critical value? Use (Use the variances unequal formula.)

One poll found that 41% of male voters will support a candidate while another found that 49% of female voters will be in support.To test whether this candidate has equal levels of support between male and Female voters, the null hypothesis should be

A recent survey reported that in a sample of 300 students who attend community colleges, 105 work at least 20 hours a week.In a sample of 225 students attending universities, only 20 students were found to Work at least 20 hours per week.What is the test value?

Donaldson Corporation wants to hire a temporary secretary.There are two employment agencies in town, and it is believed that the average hourly wages charged by both agencies are the same.Test this claim at