Question 1

At α = .05, the critical value to test the hypotheses H0: π ≥ .40, H1: π < .40 would be:

Accepted Answer

A) -1.645 
B) -1.960 
C) -2.326 
D) impossible to determine without more information. 
A) -1.645 
B) -1.960 
C) -2.326 
D) impossible to determine without more information.

Question 2

After testing a hypothesis regarding the mean, we decided not to reject H0. Thus, we are exposed to:

Accepted Answer

A) Type I error. 
B) Type II error. 
C) Either Type I or Type II error. 
D) Neither Type I nor Type II error. 
A) Type I error. 
B) Type II error. 
C) Either Type I or Type II error. 
D) Neither Type I nor Type II error.

Question 3

A Type I error can only occur if you reject H0.

Accepted Answer

A) True 
 B)False

Question 4

When testing the hypothesis H0: μ = 100 with n = 100 and σ2 = 100, we find that the sample mean is 97. The test statistic is:

Accepted Answer

A) -3.000 
B) -10.00 
C) -0.300 
D) -0.030 
A) -3.000 
B) -10.00 
C) -0.300 
D) -0.030

Question 5

A Type II error can only occur when you fail to reject H0.

Accepted Answer

A) True 
 B)False

Question 6

Which is not a step in hypothesis testing?

Accepted Answer

A) Formulate the hypotheses. 
B) Specify the desired Type I error. 
C) Find the test statistic from a table. 
D) Formulate a decision rule. 
A) Formulate the hypotheses. 
B) Specify the desired Type I error. 
C) Find the test statistic from a table. 
D) Formulate a decision rule.

Question 7

A two-tailed hypothesis test for H0: μ = 15 at α = .10 is analogous to asking if a 90 percent confidence interval for μ contains 15.

Accepted Answer

A) True 
 B)False

Question 8

The decision rule is:

Accepted Answer

A) based on the sampling distribution and chosen level of significance. 
B) specified so as to support the researcher's alternative hypothesis. 
C) chosen after selecting the sample and calculating the test statistic. 
D) specified by a panel of expert statisticians elected annually. 
A) based on the sampling distribution and chosen level of significance. 
B) specified so as to support the researcher's alternative hypothesis. 
C) chosen after selecting the sample and calculating the test statistic. 
D) specified by a panel of expert statisticians elected annually.

Question 9

After testing a hypothesis, we decided to reject the null hypothesis. Thus, we are exposed to:

Accepted Answer

A) Type I error. 
B) Type II error. 
C) Either Type I or Type II error. 
D) Neither Type I nor Type II error. 
A) Type I error. 
B) Type II error. 
C) Either Type I or Type II error. 
D) Neither Type I nor Type II error.

Question 10

For a given level of significance (α), increasing the sample size will increase the probability of Type II error because there are more ways to make an incorrect decision.

Accepted Answer

A) True 
 B)False

Question 11

The height of the power curve shows the probability of accepting a true null hypothesis.

Accepted Answer

A) True 
 B)False

Question 12

A study over a 10-year period showed that a certain mammogram test had a 50 percent rate of false positives. This indicates that:

Accepted Answer

A) about half the tests indicated cancer. 
B) about half the tests missed a cancer that exists. 
C) about half the tests showed a cancer that didn't exist. 
D) about half the women tested actually had no cancer. 
A) about half the tests indicated cancer. 
B) about half the tests missed a cancer that exists. 
C) about half the tests showed a cancer that didn't exist. 
D) about half the women tested actually had no cancer.

Question 13

Which of the following is not a valid null hypothesis?

Accepted Answer

A) H0: μ ≥ 0 
B) H0: μ ≤ 0 
C) H0: μ ≠ 0 
D) H0: μ = 0 
A) H0: μ ≥ 0 
B) H0: μ ≤ 0 
C) H0: μ ≠ 0 
D) H0: μ = 0

Question 14

In hypothesis testing, we cannot prove a null hypothesis is true.

Accepted Answer

A) True 
 B)False

Question 15

If n = 25 and α = .05 in a right-tailed test of a mean with unknown σ, the critical value is:

Accepted Answer

A) 1.960 
B) 1.645 
C) 1.711 
D) .0179 Using d.f. = 24, t.05 = 1.711 from AppendixD. 
A) 1.960 
B) 1.645 
C) 1.711 
D) .0179 Using d.f. = 24, t.05 = 1.711 from AppendixD.

Question 16

If a judge acquits every defendant, the judge will never commit a Type I error. (H0 is the hypothesis of innocence.)

Accepted Answer

A) True 
 B)False

Question 17

In a left-tailed test, a statistician got a z test statistic of -1.720. What is the p-value?

Accepted Answer

A) .4292 
B) .0709 
C) .0427 
D) .0301 
A) .4292 
B) .0709 
C) .0427 
D) .0301

Question 18

Guidelines for the Jolly Blue Giant Health Insurance Company say that the average hospitalization for a triple hernia operation should not exceed 30 hours. A diligent auditor studied records of 16 randomly chosen triple hernia operations at Hackmore Hospital and found a mean hospital stay of 40 hours with a standard deviation of 20 hours. "Aha!" she cried, "the average stay exceeds the guideline." At α = .025, the critical value for a right-tailed test of her hypothesis is:

Accepted Answer

A) 1.753 
B) 2.131 
C) 1.645 
D) 1.960 
A) 1.753 
B) 2.131 
C) 1.645 
D) 1.960

Question 19

For a sample of nine items, the critical value of Student's t for a left-tailed test of a mean at α = .05 is -1.860.

Accepted Answer

A) True 
 B)False

Question 20

For a given level of significance, the critical value of Student's t increases as n increases.

Accepted Answer

A) True 
 B)False

At α = .05, the critical value to test the hypotheses H₀: π ≥ .40, H₁: π < .40 would be:

After testing a hypothesis regarding the mean, we decided not to reject H₀. Thus, we are exposed to:

A Type I error can only occur if you reject H₀.

When testing the hypothesis H₀: μ = 100 with n = 100 and σ² = 100, we find that the sample mean is 97. The test statistic is:

A Type II error can only occur when you fail to reject H₀.

Which is not a step in hypothesis testing?

A two-tailed hypothesis test for H₀: μ = 15 at α = .10 is analogous to asking if a 90 percent confidence interval for μ contains 15.

The decision rule is:

After testing a hypothesis, we decided to reject the null hypothesis. Thus, we are exposed to:

For a given level of significance (α), increasing the sample size will increase the probability of Type II error because there are more ways to make an incorrect decision.

The height of the power curve shows the probability of accepting a true null hypothesis.

A study over a 10-year period showed that a certain mammogram test had a 50 percent rate of false positives. This indicates that:

Which of the following is not a valid null hypothesis?

In hypothesis testing, we cannot prove a null hypothesis is true.

If n = 25 and α = .05 in a right-tailed test of a mean with unknown σ, the critical value is:

If a judge acquits every defendant, the judge will never commit a Type I error. (H₀ is the hypothesis of innocence.)

In a left-tailed test, a statistician got a z test statistic of -1.720. What is the p-value?

For a sample of nine items, the critical value of Student's t for a left-tailed test of a mean at α = .05 is -1.860.

For a given level of significance, the critical value of Student's t increases as n increases.

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions and Estimation

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Time Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

Exam 9: One-Sample Hypothesis Tests

At α = .05, the critical value to test the hypotheses H0: π ≥ .40, H1: π < .40 would be:

After testing a hypothesis regarding the mean, we decided not to reject H0. Thus, we are exposed to:

A Type I error can only occur if you reject H0.

When testing the hypothesis H0: μ = 100 with n = 100 and σ2 = 100, we find that the sample mean is 97. The test statistic is:

A Type II error can only occur when you fail to reject H0.

Which is not a step in hypothesis testing?

A two-tailed hypothesis test for H0: μ = 15 at α = .10 is analogous to asking if a 90 percent confidence interval for μ contains 15.

The decision rule is:

After testing a hypothesis, we decided to reject the null hypothesis. Thus, we are exposed to:

For a given level of significance (α), increasing the sample size will increase the probability of Type II error because there are more ways to make an incorrect decision.

The height of the power curve shows the probability of accepting a true null hypothesis.

A study over a 10-year period showed that a certain mammogram test had a 50 percent rate of false positives. This indicates that:

Which of the following is not a valid null hypothesis?

In hypothesis testing, we cannot prove a null hypothesis is true.

If n = 25 and α = .05 in a right-tailed test of a mean with unknown σ, the critical value is:

If a judge acquits every defendant, the judge will never commit a Type I error. (H0 is the hypothesis of innocence.)

In a left-tailed test, a statistician got a z test statistic of -1.720. What is the p-value?

For a sample of nine items, the critical value of Student's t for a left-tailed test of a mean at α = .05 is -1.860.

For a given level of significance, the critical value of Student's t increases as n increases.

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions and Estimation

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Time Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

At α = .05, the critical value to test the hypotheses H₀: π ≥ .40, H₁: π < .40 would be:

After testing a hypothesis regarding the mean, we decided not to reject H₀. Thus, we are exposed to:

A Type I error can only occur if you reject H₀.

When testing the hypothesis H₀: μ = 100 with n = 100 and σ² = 100, we find that the sample mean is 97. The test statistic is:

A Type II error can only occur when you fail to reject H₀.

A two-tailed hypothesis test for H₀: μ = 15 at α = .10 is analogous to asking if a 90 percent confidence interval for μ contains 15.

If a judge acquits every defendant, the judge will never commit a Type I error. (H₀ is the hypothesis of innocence.)