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Question 17 of 40
2.5 Points
A long-distance telephone company claims that the mean duration of long-distance telephone calls originating in one town was greater than 9.4 minutes, which is the average for the state. Determine the conclusion of the hypothesis test assuming that the results of the sampling do not lead to rejection of the null hypothesis.
A. Conclusion: Support the claim that the mean is less than 9.4 minutes.
 
B. Conclusion: Support the claim that the mean is greater than 9.4 minutes.
 
C. Conclusion: Support the claim that the mean is equal to 9.4 minutes.
 
D. Conclusion: Do not support the claim that the mean is greater than 9.4 minutes.
 
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Question 18 of 40
2.5 Points
A nationwide study of American homeowners revealed that 65% have one or more lawn mowers. A lawn equipment manufacturer, located in Omaha, feels the estimate is too low for households in Omaha. Find the P-value for a test of the claim that the proportion with lawn mowers in Omaha is higher than 65%. Among 497 randomly selected homes in Omaha, 340 had one or more lawn mowers. Use Table 5.1 to find the best answer.
A. 0.0559
 
B. 0.1118
 
C. 0.0252
 
D. 0.0505
 
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Question 19 of 40
2.5 Points
A psychologist claims that more than 29 percent of the professional population suffers from problems due to extreme shyness. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is failure to reject the null hypothesis, state the conclusion in non-technical terms.
A. There is sufficient evidence to support the claim that the true proportion is less than 29 percent.
 
B. There is not sufficient evidence to support the claim that the true proportion is greater than 29 percent.
 
C. There is sufficient evidence to support the claim that the true proportion is equal to 29 percent.
 
D. There is sufficient evidence to support the claim that the true proportion is greater than 29 percent.
Question 20 of 40
2.5 Points

In the past, the mean running time for a certain type of flashlight battery has been 9.8 hours. The manufacturer has introduced a change in the production method and wants to perform a hypothesis test to determine whether the mean running time has increased as a result. The hypotheses are:

H0 : µ  = 9.8 hours

Ha : µ  > 9.8 hours

Suppose that the results of the sampling lead to rejection of the null hypothesis. Classify that conclusion as a Type I error, a Type II error, or a correct decision, if in fact the mean running time has not increased.

A. Type I error
 
B. Type II error
 
C. Correct decision
 
D. Can not be determined from this information
 
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Question 21 of 40
2.5 Points

The following data were analyzed using one-way analysis of variance.

ABC
342719
262321
312922
282112

Which one of the following statements is correct?

A. The purpose of the analysis is to determine whether the groups A, B, and C are independent.
 
B. The purpose of the analysis is to test the hypothesis that the population means of the three groups are equal.
 
C. The purpose of the analysis is to test the hypothesis that the population variances of the three groups are equal.
 
D. The purpose of the analysis is to test the hypothesis that the sample means of the three groups are equal.
 
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Question 22 of 40
2.5 Points
A large test statistic F tells us that the sample means __________ the data within the individual samples, which would be unlikely if the populations means really were equal (as the null hypothesis claims).
A. differ more than
 
B. differ less than
 
C. are equal to
 
D. do not vary with
Question 23 of 40
2.5 Points

One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.

 ColorblindNot ColorblindTotal
Male75360
Female13940
Total892100

Find the value of the X2 statistic for the data above.

A. 1.325
 
B. 1.318
 
C. 1.286
 
D. 1.264
Question 24 of 40
2.5 Points

One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. 

The critical value of X2 for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the X2 statistic is 3.427, state your conclusion about the relationship between gender and colorblindness.

A.

Do not reject H0. There is not sufficient evidence to support the claim that gender and colorblindness are related.

 
B.

Do not reject H0. There is sufficient evidence to support the claim that gender and colorblindness are related.

 
C.

Reject H0. There is not sufficient evidence to support the claim that gender and colorblindness are related.

 
D.

Reject H0. There is sufficient evidence to support the claim that gender and colorblindness are related.

 
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Question 25 of 40
2.5 Points

A golfer wished to find a ball that would travel more than 160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 8 times at the required speed.

Data from this test resulted in a sample mean of 163.2 yards with a sample standard deviation of 5.8 yards. Assuming normality, carry out a hypothesis test at the 0.05 significance level to determine whether the ball meets the golfer’s requirements. Use the partial t-table below to solve this problem.

 Area in one tail
 0.0250.05
 Area in two tails
Degrees of
Freedom
n - 1		0.050.10
62.4471.943
72.3651.895
82.3061.860
92.2621.833
A.

Do not reject the null hypothesis. The data do not provide sufficient
evidence that the average distance is greater than 160 yards.

 
B. Reject the null hypothesis. The data does provide sufficient evidence that the average distance is greater than 160 yards.
 
C. t= 1.2334; Critical value = 1.992
 
D. Insufficient information to answer this question.
 
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Question 26 of 40
2.5 Points

One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.

 ColorblindNot ColorblindTotal
Male75360
Female13940
Total892100

State the null and alternative hypothesis for the information above.

A.

H0: Colorblindness and gender are dependent characteristics.
Ha: Colorblindness and gender are related in some way.

 
B.

H0: Colorblindness and gender are independent characteristics.
Ha: Colorblindness and gender are not related in any way.

 
C.

H0: Colorblindness and gender are dependent characteristics.
Ha: Colorblindness and gender are not related in any way.

 
D.

H0: Colorblindness and gender are independent characteristics.
Ha: Colorblindness and gender are related in some way.

 
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Question 27 of 40
2.5 Points

Which of the following statements is true?

A. The p distribution cannot be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown.
 
B. The t distribution can be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown.
 
C. The t distribution cannot be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown.
 
D. The p distribution can be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown.
Question 28 of 40
2.5 Points

A 95% confidence interval for the mean of a normal population is found to be 15.6 < µ < 24.8. What is the margin of error?

A. 4.4
 
B. 4.6
 
C. 4.8
 
D. 5.0
Question 29 of 40
2.5 Points

A 95% confidence interval for the mean of a normal population is found to be 17.6 < µ < 23.6. What is the margin of error?

A. 2.0
 
B. 2.7
 
C. 3.0
 
D. 4.0
Question 30 of 40
2.5 Points

A 95% confidence interval for the mean of a normal population is found to be 13.2 < µ < 22.4. What is the margin of error?

A. 4.6
 
B. 4.4
 
C. 4.2
 
D. 5.6
Question 31 of 40
2.5 Points
The __________ test statistic is for the one-way analysis of variance.
A. P-Value
 
B. t
 
C. F
 
D. p
 
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Question 32 of 40
2.5 Points

One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.

 ColorblindNot ColorblindTotal
Male75360
Female13940
Total892100

If gender and colorblindness are independent, find the expected values corresponding to the male combinations of gender and colorblindness.

A. Colorblind Male 4.8; Not Colorblind Male 55.2
 
B. Colorblind Male 6.8; Not Colorblind Male 53.2
 
C. Colorblind Male 4.8; Not Colorblind Male 55.4
 
D. Colorblind Male 4.8; Not Colorblind Male 56.2
 
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Question 33 of 40
2.5 Points

The margin of error in estimating the population mean of a normal population is E = 9.3 when the sample size is 15. If the sample size had been 18 and the sample standard deviation did not change, would the margin of error be larger or smaller than 9.3? Explain your answer.

A. Smaller. E decreases as the square root of the sample size gets larger.
 
B. Smaller. E increases as the square root of the sample size gets larger.
 
C. Larger. E decreases as the square root of the sample size gets larger.
 
D. Larger. E increases as the square root of the sample size gets larger.
Question 34 of 40
2.5 Points

One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.

 ColorblindNot ColorblindTotal
Male85260
Female23840
Total1090100

If gender and colorblindness are independent, find the expected values corresponding to the four combinations of gender and colorblindness, and enter them in the following table along with row and column totals.

 ColorblindNot ColorblindTotal
Male   
Female   
Total   

 

A. Male Colorblind 6.0; Male Not Colorblind 54.0
 
B. Male Colorblind 7.0; Male Not Colorblind 53.0
 
C. Male Colorblind 8.0; Male Not Colorblind 52.0
 
D. Male Colorblind 6.0; Male Not Colorblind 53.0
 
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Question 35 of 40
2.5 Points

A golfer wished to find a ball that would travel more than 160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 8 times at the required speed. State the null and alternative hypotheses for this test.

A.

H0: µ = 160; Ha: µ > 150

 
B.

H0: µ = 150; Ha: µ > 150

 
C.

H0: µ = 160; Ha: µ > 160

 
D.

H0: µ = 140; Ha: µ > 160

 
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Question 36 of 40
2.5 Points

A simple random sample from a normal distribution is taken in order to obtain a 95% confidence interval for the population mean. If the sample size is 8, the sample mean x̄ is 22, and the sample standard deviation s is 6.3, what is the margin of error? Show your answer to 2 decimal places.

A. df = 7; E = 3.3445.38 = 5.6566
 
B. df = 8; E = 3.3445.38 = 5.6566
 
C. df = 6; E = 2.3656.38 = 5.769
 
D. df = 7; E = 2.3656.38 = 5.869
 
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Question 37 of 40
2.5 Points

A golfer wished to find a ball that would travel more than 180 yards when hit with his 5-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 7 times at the required speed.

Data from this test resulted in a sample mean of 184.2 yards and a sample standard deviation of 5.8 yards. Assuming normality, carry out a hypothesis test at the 0.05 significance level to determine whether the ball meets the golfer’s requirements. Use the partial t-table below.

 Area in one tail
 0.0250.05
 Area in two tails
Degrees of
Freedom
n - 1		0.050.10
62.4471.943
72.3651.895
82.3061.860
92.2621.833
A.

Reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 180 yards.

 
B. Reject the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 180 yards.
 
C. Do not reject the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 180 yards.
 
D. Do not reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 180 yards.
 
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Question 38 of 40
2.5 Points

Which of the following statements is true?

A. The t distribution cannot be used when finding a confidence interval for the population mean with a small sample whenever the sample comes from a symmetric population.
 
B. The t distribution can be used when finding a confidence interval for the population mean with a small sample whenever the sample comes from a symmetric population.
 
C. The p distribution can be used when finding a confidence interval for the population mean with a small sample whenever the sample comes from a symmetric population.
 
D. The p distribution can be used when finding a confidence interval for the population mean with a small sample whenever the sample comes from a symmetric population.
 
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Question 39 of 40
2.5 Points

One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent.

The critical value of X2 for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the X2 statistic is 4.613, state your conclusion about the relationship between gender and colorblindness.

A.

Reject H0. There is not sufficient evidence to support the claim that gender and colorblindness are related.

 
B.

Reject H0. There is sufficient evidence to support the claim that gender and colorblindness are related.

 
C.

Do not Reject H0. There is sufficient evidence to support the claim that gender and colorblindness are related.

 
D.

Do not Reject H0. There is not sufficient evidence to support the claim that gender and colorblindness are related.

 
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Question 40 of 40
2.5 Points

One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent.

The critical value of X2 for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the X2  statistic is 3.179, state your conclusion about the relationship between gender and colorblindness.

A.

Do not reject H0.

 
B.

Reject H0.

 
C.

There is sufficient evidence to support the claim that gender and colorblindness are not related.

 
D.

There is not sufficient evidence to accept or reject H0.

 
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