Question 2 of 40

0.0/ 2.5 Points

The owner of a football team claims that the average attendance at home games is over 3000, and he is therefore justified in moving the team to a city with a larger stadium. 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 nontechnical terms.
A. There is sufficient evidence to support the claim that the mean attendance is greater than 3000.

B. There is sufficient evidence to support the claim that the mean attendance is equal to 3000.

C. There is not sufficient evidence to support the claim that the mean attendance is greater than 3000.

D. There is not sufficient evidence to support the claim that the mean attendance is less than 3000.


Question 3 of 40

0.0/ 2.5 Points

A psychologist claims that more than 19 percent of the population suffers from professional problems due to extreme shyness. Assume that a hypothesis test of the claim has been conducted and that the conclusion of the test was to reject the null hypothesis. Identify the population to which the results of the test apply.
A. The population is all shy workers.

B. The population cannot be identified from the description of the study.

C. The population is all American workers.

D. The population is all American professional workers (doctors, lawyers, CPA’s, and the like..


Question 5 of 40

0.0/ 2.5 Points

A longdistance telephone company claims that the mean duration of longdistance 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.


Question 8 of 40

0.0/ 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 nontechnical 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 10 of 40

0.0/ 2.5 Points

A supplier of DVDs claims that no more than 1% of the DVDs are defective. In a random sample of 600 DVDs, it is found that 3% are defective, but the supplier claims that this is only a sample fluctuation. At the 0.01 level of significance, test the supplier’s claim that no more than 1% are defective.
A. Do not reject the null hypothesis and conclude that there is evidence to support the claim that more than 1% of the DVDs are defective.

B. Reject the null hypothesis and conclude that there is insufficient evidence to support the claim that more than 1% of the DVDs are defective.

C. Do not reject the null hypothesis and conclude that there is insufficient evidence to support the claim that more than 1% of the DVDs are defective.

D. Reject the null hypothesis and conclude that there is sufficient evidence to support the claim that more than 1% of the DVDs are defective.


Question 11 of 40

0.0/ 2.5 Points

A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO is less than 1 in every one thousand. State the null hypothesis and the alternative hypothesis for a test of significance.
A.
H_{0}: p = 0.001 H_{a}: p > 0.001

B.
H_{0}: p = 0.001 H_{a}: p < 0.001

C.
H_{0}: p > 0.001 H_{a}: p = 0.001

D.
H_{0}: p < 0.001 H_{a}: p = 0.001


Question 12 of 40

0.0/ 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:
H_{0} : µ = 9.8 hours
H_{a} : 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


Question 15 of 40

0.0/ 2.5 Points

In 1990, the average duration of longdistance telephone calls originating in one town was 9.4 minutes. A longdistance telephone company wants to perform a hypothesis test to determine whether the average duration of longdistance phone calls has changed from the 1990 mean of 9.4 minutes. The mean duration for a random sample of 50 calls originating in the town was 8.6 minutes. Does the data provide sufficient evidence to conclude that the mean call duration, µ, is different from the 1990 mean of 9.4 minutes? Perform the appropriate hypothesis test using a significance level of 0.01. Assume that s = 4.8 minutes.
A. With a z of 1.2 there is sufficient evidence to conclude that the mean
value has changed from the 1990 mean of 9.4 minutes.

B. With a Pvalue of 0.2302 there is not sufficient evidence to conclude
that the mean value is less than the 1990 mean of 9.4 minutes.

C. With a Pvalue of 0.2302 there is sufficient evidence to conclude that
the mean value is less than the 1990 mean of 9.4 minutes.

D. With a z of –1.2 there is not sufficient evidence to conclude that the
mean value has changed from the 1990 mean of 9.4 minutes.


Question 18 of 40

0.0/ 2.5 Points

A researcher wants to check the claim that convicted burglars spend an average of 18.7 months in jail. She takes a random sample of 35 such cases from court files and finds that months. Assume that the population standard deviation is 7 months. Test the null hypothesis that µ = 18.7 at the 0.05 significance level.
A.
Do not reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months is supported.

B.
Do not reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months cannot be supported.

C.
Reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months is supported.

D.
Reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months cannot be supported.





Question 22 of 40

0.0/ 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 24 of 40

0.0/ 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.

Colorblind

Not Colorblind

Total

Male

7

53

60

Female

1

39

40

Total

8

92

100

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


Question 25 of 40

0.0/ 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.


Question 26 of 40

0.0/ 2.5 Points

A golfer wished to find a ball that would travel more than 180 yards when hit with his 5iron 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 ttable below.

Area in one tail


0.025

0.05


Area in two tails

Degrees of
Freedom
n  1

0.05

0.10

6

2.447

1.943

7

2.365

1.895

8

2.306

1.860

9

2.262

1.833

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.




Question 30 of 40

2.5/ 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.

Colorblind

Not Colorblind

Total

Male

7

53

60

Female

1

39

40

Total

8

92

100

If gender and colorblindness are independent, find the expected values corresponding to the female combinations of gender and colorblindness.
A. Colorblind Female 4.8; Not Colorblind Female 55.2

B. Colorblind Female 3.2; Not Colorblind Female 36.8

C. Colorblind Female 4.8; Not Colorblind Female 35.2

D. Colorblind Female 3.8; Not Colorblind Female 36.2






Question 35 of 40

0.0/ 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 36 of 40

0.0/ 2.5 Points

A golfer wished to find a ball that would travel more than 170 yards when hit with his 6iron with a club head speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 12 times at the required speed.
Data from this test had a sample mean of 171.6 yards with a sample standard deviation of 2.4 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 ttable below.

Area in one tail


0.025

0.05


Area in two tails

Degrees of
Freedom
n  1

0.05

0.10

6

2.447

1.943

7

2.365

1.895

8

2.306

1.860

9

2.262

1.833

A.
Accept the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 170 yards.

B. Accept the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 170 yards.

C. Reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 170 yards.

D. Reject the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 170 yards.


Question 37 of 40

0.0/ 2.5 Points

Which of the following statements is true?
A.
The t distribution can be used when finding a confidence interval for the population mean whenever the sample size is small.

B. The p distribution can be used when finding a confidence interval for the population mean whenever the sample size is small.

C. The t distribution cannot be used when finding a confidence interval for the population mean whenever the sample size is small.

D. The p distribution cannot be used when finding a confidence interval for the sample mean whenever the sample size is small.





Question 2 of 40
0.0/ 2.5 Points
A twotailed test is conducted at the 0.10 significance level. What is the Pvalue required to reject the null hypothesis?
A. Greater than or equal to .010
B. Greater than or equal to 0.05
C. Less than or equal to 0.10
D. Less than or equal to 0.05
Question 4 of 40
0.0/ 2.5 Points
A manufacturer claims that the mean amount of juice in its 16 ounce bottles is 16.1 ounces. A consumer advocacy group wants to perform a hypothesis test to determine whether the mean amount is actually less than this. The mean volume of juice for a random sample of 70 bottles was 15.94 ounces. Do the data provide sufficient evidence to conclude that the mean amount of juice for all 16ounce bottles, µ, is less than 16.1 ounces? Perform the appropriate hypothesis test using a significance level of 0.10. Assume that s = 0.9 ounces.
A.
The z of  1.49 provides sufficient evidence to conclude that the mean amount of juice is less than 16.1 oz.
B.
The z of  1.49 does not provide sufficient evidence to conclude that the mean amount of juice is less than 16.1 oz.
C.
The z of  0.1778 does not provide sufficient evidence to conclude that the mean amount of juice is less than 16.1 oz.
D.
The z of  0.1778 provides sufficient evidence to conclude that the mean amount of juice is less than 16.1 oz.
Question 9 of 40
0.0/ 2.5 Points
If a fan purchased a bag with 30 peanuts, what is the lowest level at which this would be a significant event?
A. 0.05
B. 0.025
C. 0.01
D. It is not significant at any of the levels given
Question 12 of 40
0.0/ 2.5 Points
A twotailed test is conducted at the 5% significance level. Which of the zscores below is the smallest one that leads to rejection of the null hypothesis?
A. 1.12
B. 1.48
C. 1.84
D. 2.15
Question 17 of 40
0.0/ 2.5 Points
At one school, the mean amount of time that tenthgraders spend watching television each week is 18.4 hours. The principal introduces a campaign to encourage the students to watch less television. One year later, the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased.
Formulate the null and alternative hypotheses for the study described.
A.
Ho: µ = 18.4 hours H a : µ ¹ 18.4 hours
B.
Ho: µ = 18.4 hours H a : µ < 18.4 hours
C.
Ho: µ ³ 18.4 hours H a : µ < 18.4 hours
D.
Ho: µ = 18.4 hours H a : µ > 18.4 hours
Question 28 of 40
0.0/ 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
Question 32 of 40
0.0/ 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.