Deck 9: Fundamentals of Hypothesis Testing: One-Sample Tests

Question 1

If a researcher does not reject a true null hypothesis, she has made a ________ decision.

Answer 1

correct

Question 2

If a researcher rejects a true null hypothesis, she has made a ________ error.

Answer 2

Type I

Question 3

If an economist wishes to determine whether there is evidence that mean family income in a community equals $50,000

A) either a one-tail or two-tail test could be used with equivalent results.
B) a one-tail test should be utilized.
C) a two-tail test should be utilized.
D) None of the above.

Answer 3

a two-tail test should be utilized.

Question 4

If the Type I error (α) for a given test is to be decreased, then for a fixed sample size n

A) the Type II error (β) will also decrease.
B) the Type II error (β) will increase.
C) the power of the test will increase.
D) a one-tail test must be utilized.

Question 5

A Type I error is committed when

A) you reject a null hypothesis that is true.
B) you don't reject a null hypothesis that is true.
C) you reject a null hypothesis that is false.
D) you don't reject a null hypothesis that is false.

Question 6

If a researcher does not reject a false null hypothesis, she has made a ________ error.

Question 7

If the p-value is less than α in a two-tail test,

A) the null hypothesis should not be rejected.
B) the null hypothesis should be rejected.
C) a one-tail test should be used.
D) no conclusion should be reached.

Question 8

Which of the following would be an appropriate alternative hypothesis?

A) The mean of a population is equal to 55.
B) The mean of a sample is equal to 55.
C) The mean of a population is greater than 55.
D) The mean of a sample is greater than 55.

Question 9

For a given level of significance (α), if the sample size n is increased, the probability of a Type II error (β)

A) will decrease.
B) will increase.
C) will remain the same.
D) cannot be determined.

Question 10

Which of the following would be an appropriate null hypothesis?

A) The mean of a population is equal to 55.
B) The mean of a sample is equal to 55.
C) The mean of a population is greater than 55.
D) Only A and C are appropriate.

Question 11

If a test of hypothesis has a Type I error probability (α) of 0.01, it means that

A) if the null hypothesis is true, you don't reject it 1% of the time.
B) if the null hypothesis is true, you reject it 1% of the time.
C) if the null hypothesis is false, you don't reject it 1% of the time.
D) if the null hypothesis is false, you reject it 1% of the time.

Question 12

Which of the following would be an appropriate null hypothesis?

A) The population proportion is less than 0.65.
B) The sample proportion is less than 0.65.
C) The population proportion is not less than 0.65.
D) The sample proportion is no less than 0.65.

Question 13

You know that the level of significance (α) of a test is 5%, you can tell that the probability of committing a Type II error (β) is

A) 2.5%.
B) 95%.
C) 97.5%.
D) unknown.

Question 14

The power of a test is measured by its capability of

A) rejecting a null hypothesis that is true.
B) not rejecting a null hypothesis that is true.
C) rejecting a null hypothesis that is false.
D) not rejecting a null hypothesis that is false.

Question 15

For a given sample size n, if the level of significance (α) is decreased, the power of the test

A) will increase.
B) will decrease.
C) will remain the same.
D) cannot be determined.

Question 16

If an economist wishes to determine whether there is evidence that mean family income in a community exceeds $50,000

A) either a one-tail or two-tail test could be used with equivalent results.
B) a one-tail test should be utilized.
C) a two-tail test should be utilized.
D) None of the above.

Question 17

You know that the probability of committing a Type II error (β) is 5%, you can tell that the power of the test is

A) 2.5%.
B) 95%.
C) 97.5%.
D) unknown.

Question 18

Which of the following would be an appropriate alternative hypothesis?

A) The population proportion is less than 0.65.
B) The sample proportion is less than 0.65.
C) The population proportion is not less than 0.65.
D) The sample proportion is not less than 0.65.

Question 19

A Type II error is committed when

A) you reject a null hypothesis that is true.
B) you don't reject a null hypothesis that is true.
C) you reject a null hypothesis that is false.
D) you don't reject a null hypothesis that is false.

Question 20

If a researcher rejects a false null hypothesis, she has made a ________ decision.

Question 21

How many tissues should the Kimberly Clark Corporation package of Kleenex contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: X = 52, S = 22. Suppose the alternative you wanted to test was H₁: μ < 60. State the correct rejection region for α = 0.05.

A) Reject H₀ if t > 1.6604.
B) Reject H₀ if t < -1.6604.
C) Reject H₀ if t > 1.9842 or Z < -1.9842.
D) Reject H₀ if t < -1.9842.

Question 22

How many tissues should the Kimberly Clark Corporation package of Kleenex contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: X = 52, S = 22. Suppose the test statistic does fall in the rejection region at α = 0.05. Which of the following decision is correct?

A) At α = 0.05, you do not reject H₀.
B) At α = 0.05, you reject H₀.
C) At α = 0.10, you do not reject H₀.
D) At α = 0.10, you reject H₀.

Question 23

The value that separates a rejection region from a non-rejection region is called the ________.

Question 24

How many tissues should the Kimberly Clark Corporation package of Kleenex contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: X = 52, S = 22. Give the null and alternative hypotheses to determine if the number of tissues used during a cold is less than 60.

A) H₀: μ ≤ 60 and H₁: μ > 60.
B) H₀: μ ≥ 60 and H₁: μ < 60.
C) H₀: X ≥ 60 and H₁: X < 60.
D) H₀: X = 52 and H₁: X ≠ 52.

Question 25

The power of a statistical test is

A) the probability of not rejecting H₀ when it is false.
B) the probability of rejecting H₀ when it is true.
C) the probability of not rejecting H₀ when it is true.
D) the probability of rejecting H₀ when it is false.

Question 26

How many tissues should the Kimberly Clark Corporation package of Kleenex contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: X = 52, S = 22. Using the sample information provided, calculate the value of the test statistic.

A) t = (52 - 60)/22
B) t = (52 - 60)/(22/100)
C) t = (52 - 60)/(22/100²)
D) t = (52 - 60)/(22/10)

Question 27

Suppose we wish to test H₀: μ ≤ 47 versus H₁: μ > 47. What will result if we conclude that the mean is greater than 47 when its true value is really 52?

A) We have made a Type I error.
B) We have made a Type II error.
C) We have made a correct decision.
D) None of the above is correct.

Question 28

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. If she wants to have a level of significance at 0.01, what rejection region should she use?

A) Reject H₀ if t < -2.3263.
B) Reject H₀ if t < -2.5758.
C) Reject H₀ if t > 2.3263.
D) Reject H₀ if t > 2.5758.

Question 29

Which of the following statements is not true about the level of significance in a hypothesis test?

A) The larger the level of significance, the more likely you are to reject the null hypothesis.
B) The level of significance is the maximum risk we are willing to accept in making a Type I error.
C) The significance level is also called the α level.
D) The significance level is another name for Type II error.

Question 30

If, as a result of a hypothesis test, you reject the null hypothesis when it is false, then you have committed

A) a Type II error.
B) a Type I error.
C) no error.
D) an acceptance error.

Question 31

You have created a 95% confidence interval for μ with the result 10 ≤ μ ≤ 15. What decision will you make if we test H₀: μ = 16 versus H₁: μ ≠ 16 at α = 0.01?

A) Reject H₀ in favor of H₁.
B) Do not reject H₀ in favor of H₁.
C) Fail to reject H₀ in favor of H₁.
D) You cannot tell what our decision will be from the information given.

Question 32

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. The appropriate hypotheses to test are:

A) H₀: μ ≥ 30 versus H₁: μ < 30.
B) H₀: μ ≤ 30 versus H₁: μ > 30.
C) H₀: X ≥ 30 versus H₁: X < 30.
D) H₀: X ≤ 30 versus H₁: X > 30.

Question 33

The symbol for the power of a statistical test is

A) α.
B) 1 - α.
C) β.
D) 1 - β.

Question 34

A ________ is a numerical quantity computed from the data of a sample and is used in reaching a decision on whether or not to reject the null hypothesis.

A) significance level
B) critical value
C) test statistic
D) parameter

Question 35

It is possible to directly compare the results of a confidence interval estimate to the results obtained by testing a null hypothesis if

A) a two-tail test for μ is used.
B) a one-tail test for μ is used.
C) Both of the previous statements are true.
D) None of the previous statements is true.

Question 36

Suppose you want to test H₀: μ ≥ 30 versus H₁: μ < 30. Which of the following possible sample results based on a sample of size 36 gives the strongest evidence to reject H₀ in favor of H₁?

A) X = 28, S = 6
B) X = 27, S = 4
C) X = 32, S = 2
D) X = 26, S = 9

Question 37

You have created a 95% confidence interval for μ with the result 10 ≤ μ ≤ 15. What decision will you make if you test H₀: μ = 16 versus H₁: μ ≠ 16 at α = 0.05?

A) Reject H₀ in favor of H₁.
B) Do not reject H₀ in favor of H₁.
C) Fail to reject H₀ in favor of H₁.
D) We cannot tell what our decision will be from the information given.

Question 38

You have created a 95% confidence interval for μ with the result 10 ≤ μ ≤ 15. What decision will you make if we test H₀: μ = 16 versus H₁: μ ≠ 16 at α = 0.10?

A) Reject H₀ in favor of H₁.
B) Do not reject H₀ in favor of H₁.
C) Fail to reject H₀ in favor of H₁.
D) We cannot tell what our decision will be from the information given.

Question 39

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. If she wants to have a level of significance at 0.01, what decision should she make?

A) Reject H₀.
B) Reject H₁.
C) Do not reject H₀.
D) We cannot tell what her decision should be from the information given.

Question 40

How many tissues should the Kimberly Clark Corporation package of Kleenex contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: X = 52, S = 22. Suppose the test statistic does fall in the rejection region at α = 0.05. Which of the following conclusion is correct?

A) At α = 0.05, there is not sufficient evidence to conclude that the mean number of tissues used during a cold is 60 tissues.
B) At α = 0.05, there is sufficient evidence to conclude that the mean number of tissues used during a cold is 60 tissues.
C) At α = 0.05, there is insufficient evidence to conclude that the mean number of tissues used during a cold is not 60 tissues.
D) At α = 0.10, there is sufficient evidence to conclude that the mean number of tissues used during a cold is not 60 tissues.

Question 41

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors results in 83 who indicate that they recommend aspirin. The value of the test statistic in this problem is approximately equal to

A) -4.12.
B) -2.33.
C) -1.86.
D) -0.07.

Question 42

A manager of the credit department for an oil company would like to determine whether the mean monthly balance of credit card holders is equal to $75. An auditor selects a random sample of 100 accounts and finds that the mean owed is $83.40 with a sample standard deviation of $23.65. If you were to conduct a test to determine whether the auditor should conclude that there is evidence that the mean balance is different from $75, which test would you use?

A) Z test of a population mean
B) Z test of a population proportion
C) t test of population mean
D) t test of a population proportion

Question 43

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. State the test of hypothesis that is of interest to the rental chain.

A) H₀: π ≤ 0.32 versus H₁: π > 0.32
B) H₀: π ≤ 0.25 versus H₁: π > 0.25
C) H₀: π ≤ 5,000 versus H₁: π > 5,000
D) H₀: μ ≤ 5,000 versus H₁: μ > 5,000

Question 44

A manager of the credit department for an oil company would like to determine whether the mean monthly balance of credit card holders is equal to $75. An auditor selects a random sample of 100 accounts and finds that the mean owed is $83.40 with a sample standard deviation of $23.65. If you wanted to test whether the mean balance is different from $75 and decided to reject the null hypothesis, what conclusion could you reach?

A) There is not evidence that the mean balance is $75.
B) There is not evidence that the mean balance is not $75.
C) There is evidence that the mean balance is $75.
D) There is evidence that the mean balance is not $75.

Question 45

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. The value of the test statistic in this problem is approximately equal to

A) 2.80.
B) 2.60.
C) 1.94.
D) 1.30.

Question 46

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. The rental chain's conclusion from the hypothesis test using a 5% level of significance is

A) to open a new store.
B) not to open a new store.
C) to delay opening a new store until additional evidence is collected.
D) We cannot tell what the decision should be from the information given.

Question 47

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the null hypothesis would be rejected.

Question 48

An entrepreneur is considering the purchase of a coin-operated laundry. The current owner claims that over the past 5 years, the mean daily revenue was $675 with a population standard deviation of $75. A sample of 30 days reveals a daily mean revenue of $625. If you were to test the null hypothesis that the daily mean revenue was $675, which test would you use?

A) Z test of a population mean
B) Z test of a population proportion
C) t test of population mean
D) t test of a population proportion

Question 49

The marketing manager for an automobile manufacturer is interested in determining the proportion of new compact-car owners who would have purchased a knee airbag if it had been available for an additional cost of $300. The manager believes from previous information that the proportion is 0.30. Suppose that a survey of 200 new compact-car owners is selected and 79 indicate that they would have purchased the knee airbag. If you were to conduct a test to determine whether there is evidence that the proportion is different from 0.30 and decided not to reject the null hypothesis, what conclusion could you reach?

A) There is sufficient evidence that the proportion is 0.31.
B) There is not sufficient evidence that the proportion is 0.31.
C) There is sufficient evidence that the proportion is 0.30.
D) There is not sufficient evidence that the proportion is not 0.30.

Question 50

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. The decision on the hypothesis test using a 5% level of significance is

A) to reject H₀ in favor of H₁.
B) to accept H₀ in favor of H₁.
C) to fail to reject H₀ in favor of H₁.
D) We cannot tell what the decision should be from the information given.

Question 51

An entrepreneur is considering the purchase of a coin-operated laundry. The current owner claims that over the past 5 years, the mean daily revenue was $675 with a population standard deviation of $75. A sample of 30 days reveals a daily mean revenue of $625. If you were to test the null hypothesis that the daily mean revenue was $675 and decide not to reject the null hypothesis, what can you conclude?

A) There is not enough evidence to conclude that the daily mean revenue was $675.
B) There is not enough evidence to conclude that the daily mean revenue was not $675.
C) There is enough evidence to conclude that the daily mean revenue was $675.
D) There is enough evidence to conclude that the daily mean revenue was not $675.

Question 52

A major DVD rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with DVD players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have DVD players. The p-value associated with the test statistic in this problem is approximately equal to

A) 0.0100.
B) 0.0051.
C) 0.0026.
D) 0.0013.

Question 53

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. What is the p-value associated with the test statistic?

A) 0.3577
B) 0.1423
C) 0.0780
D) 0.02

Question 54

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors was selected. Suppose that the test statistic is -2.20. Can you conclude that H₀ should be rejected at the (a) α = 0.10, ?(b) α = 0.05, and (c) α = 0.01 level of Type I error?

A) (a) yes; (b) yes; (c) yes
B) (a) no; (b) no; (c) no
C) (a) no; (b) no; (c) yes
D) (a) yes; (b) yes; (c) no

Question 55

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the parameter the manager is interested in is

A) the mean number of defective light bulbs per case produced at the plant.
B) the mean number of defective light bulbs per case among the 46 cases.
C) the mean number of defective light bulbs per case produced during the morning shift.
D) the proportion of cases with defective light bulbs produced at the plant.

Question 56

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. If she wants to have a level of significance at 0.01 what conclusion can she make?

A) There is not sufficient evidence that the mean age of her customers is greater than 30.
B) There is sufficient evidence that the mean age of her customers is greater than 30.
C) There is not sufficient evidence that the mean age of her customers is not greater than 30.
D) There is sufficient evidence that the mean age of her customers is not greater than 30.

Question 57

The marketing manager for an automobile manufacturer is interested in determining the proportion of new compact-car owners who would have purchased a side curtain air bag if it had been available for an additional cost of $300. The manager believes from previous information that the proportion is 0.30. Suppose that a survey of 200 new compact-car owners is selected and 79 indicate that they would have purchased the side curtain air bags. If you were to conduct a test to determine whether there is evidence that the proportion is different from 0.30, which test would you use?

A) Z test of a population mean
B) Z test of a population proportion
C) t test of population mean
D) t test of a population proportion

Question 58

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, what critical value should the manager use to determine the rejection region?

A) 1.6794
B) 1.3011
C) 1.3006
D) 0.6800

Question 59

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors was selected. Suppose you reject the null hypothesis. What conclusion can you reach?

A) There is not sufficient evidence that the proportion of doctors who recommend aspirin is not less than 0.90.
B) There is sufficient evidence that the proportion of doctors who recommend aspirin is not less than 0.90.
C) There is not sufficient evidence that the proportion of doctors who recommend aspirin is less than 0.90.
D) There is sufficient evidence that the proportion of doctors who recommend aspirin is less than 0.90.

Question 60

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, state the alternative hypothesis for this study.

Question 61

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the null hypothesis would be rejected if a 5% probability of committing a Type I error is allowed.

Question 62

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the lowest level of significance at which the null hypothesis can be rejected is ________.

Question 63

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, if these data were used to perform a two-tail test, the p-value would be 0.042.

Question 64

Suppose, in testing a hypothesis about a mean, the Z test statistic is computed to be 2.04. The null hypothesis should be rejected if the chosen level of significance is 0.01 and a two-tail test is used.

Question 65

The statement of the null hypothesis always contains an equality.

Question 66

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the null hypothesis would be rejected if a 1% probability of committing a Type I error is allowed.

Question 67

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the manager can conclude that there is sufficient evidence to show that the mean number of defective bulbs per case is greater than 20 during the morning shift with no more than a 5% probability of incorrectly rejecting the true null hypothesis.

Question 68

A sample is used to obtain a 95% confidence interval for the mean of a population. The confidence interval goes from 15 to 19. If the same sample had been used to test the null hypothesis that the mean of the population is equal to 20 versus the alternative hypothesis that the mean of the population differs from 20, the null hypothesis could be rejected at a level of significance of 0.10.

Question 69

A sample is used to obtain a 95% confidence interval for the mean of a population. The confidence interval goes from 15 to 19. If the same sample had been used to test the null hypothesis that the mean of the population is equal to 20 versus the alternative hypothesis that the mean of the population differs from 20, the null hypothesis could be rejected at a level of significance of 0.05.

Question 70

The smaller the p-value, the stronger is the evidence against the null hypothesis.

Question 71

The test statistic measures how close the computed sample statistic has come to the hypothesized population parameter.

Question 72

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the manager can conclude that there is sufficient evidence to show that the mean number of defective bulbs per case is greater than 20 during the morning shift using a level of significance of 0.10.

Question 73

Suppose, in testing a hypothesis about a mean, the p-value is computed to be 0.034. The null hypothesis should be rejected if the chosen level of significance is 0.01.

Question 74

Suppose, in testing a hypothesis about a mean, the p-value is computed to be 0.043. The null hypothesis should be rejected if the chosen level of significance is 0.05.

Question 75

The larger the p-value, the more likely you are to reject the null hypothesis.

Question 76

A sample is used to obtain a 95% confidence interval for the mean of a population. The confidence interval goes from 15 to 19. If the same sample had been used to test the null hypothesis that the mean of the population is equal to 20 versus the alternative hypothesis that the mean of the population differs from 20, the null hypothesis could be rejected at a level of significance of 0.02.

Question 77

A sample is used to obtain a 95% confidence interval for the mean of a population. The confidence interval goes from 15 to 19. If the same sample had been used to test the null hypothesis that the mean of the population is equal to 18 versus the alternative hypothesis that the mean of the population differs from 18, the null hypothesis could be rejected at a level of significance of 0.05.

Question 78

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the manager can conclude that there is sufficient evidence to show that the mean number of defective bulbs per case is greater than 20 during the morning shift with no more than a 1% probability of incorrectly rejecting the true null hypothesis.

Question 79

TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

Referring to Table 9-1, the evidence proves beyond a doubt that the mean number of defective bulbs per case is greater than 20 during the morning shift.

Question 80

In a hypothesis test, it is irrelevant whether the test is a one-tail or two-tail test.