Question 1

Which of the following is incorrect?

Accepted Answer

A) The level of significance is the probability of making a Type I error. 
B) Lowering both α and β at once will require a higher sample size. 
C) The probability of rejecting a true null hypothesis increases as n increases. 
D) When Type I error increases, Type II error must decrease, ceteris paribus. 
A) The level of significance is the probability of making a Type I error. 
B) Lowering both α and β at once will require a higher sample size. 
C) The probability of rejecting a true null hypothesis increases as n increases. 
D) When Type I error increases, Type II error must decrease, ceteris paribus.

Question 2

Which is not true of p-values?

Accepted Answer

A) When they are small, we want to reject H0. 
B) They measure the probability of an incorrect decision. 
C) They show the chance of Type I error if we reject H0. 
D) They do not require α to be specified a priori. 
A) When they are small, we want to reject H0. 
B) They measure the probability of an incorrect decision. 
C) They show the chance of Type I error if we reject H0. 
D) They do not require α to be specified a priori.

Question 3

The researcher's null hypothesis is H0: σ2 = 420. A sample of n = 18 items yields a sample variance of s2 = 512. The critical values of chi-square for a two-tailed test at α = .05 are:

Accepted Answer

A) 8.672 and 27.59 
B) 7.564 and 30.19 
C) -1.960 and +1.960 
D) 9.390 and 28.87 
A) 8.672 and 27.59 
B) 7.564 and 30.19 
C) -1.960 and +1.960 
D) 9.390 and 28.87

Question 4

In a right-tailed test, the null hypothesis is rejected when the value of the test statistic exceeds the critical value.

Accepted Answer

A) True 
 B)False

Question 5

The process that produces Sonora Bars (a type of candy) is intended to produce bars with a mean weight of 56 gm. The process standard deviation is known to be 0.77 gm. A random sample of 49 candy bars yields a mean weight of 55.82 gm. Find the p-value for a test to see whether the candy bars are smaller than they are supposed to be.

Accepted Answer

A) Between .05 and .10 
B) Between .025 and .05 
C) Between .01 and .025 
D) Less than .01 
A) Between .05 and .10 
B) Between .025 and .05 
C) Between .01 and .025 
D) Less than .01

Question 6

The critical value in a hypothesis test:

Accepted Answer

A) is a test statistic calculated from the sample. 
B) is a contradictory result from a different test. 
C) is a cutoff between the rejection and nonrejection regions. 
D) is another name for level of significance. 
A) is a test statistic calculated from the sample. 
B) is a contradictory result from a different test. 
C) is a cutoff between the rejection and nonrejection regions. 
D) is another name for level of significance.

Question 7

For a test of a mean, which of the following is incorrect?

Accepted Answer

A) H0 is rejected when the calculated p-value is less than the critical value of the test statistic. 
B) In a right-tailed test, we reject H0 when the test statistic exceeds the critical value. 
C) The critical value is based on the researcher's chosen level of significance. 
D) If H0: μ ≤ 100 and H1: μ > 100, then the test is right-tailed. 
A) H0 is rejected when the calculated p-value is less than the critical value of the test statistic. 
B) In a right-tailed test, we reject H0 when the test statistic exceeds the critical value. 
C) The critical value is based on the researcher's chosen level of significance. 
D) If H0: μ ≤ 100 and H1: μ > 100, then the test is right-tailed.

Question 8

The researcher's null hypothesis is H0: σ2 ≤ 22. A sample of n = 25 items yields a sample variance of s2 = 28.5. The critical value of chi-square for a right-tailed test at α = .05 is:

Accepted Answer

A) 1.960 
B) 1.645 
C) 13.85 
D) 36.42 
A) 1.960 
B) 1.645 
C) 13.85 
D) 36.42

Question 9

The critical value in a hypothesis test:

Accepted Answer

A) is calculated from the sample data. 
B) usually is .05 or .01 in most statistical tests. 
C) separates the acceptance and rejection regions. 
D) depends on the value of the test statistic. 
A) is calculated from the sample data. 
B) usually is .05 or .01 in most statistical tests. 
C) separates the acceptance and rejection regions. 
D) depends on the value of the test statistic.

Question 10

The critical value in a hypothesis test:

Accepted Answer

A) is derived from the sample. 
B) is determined by α and the type of test. 
C) is another name for the null hypothesis. 
D) is a dissenting view by scientific critics. 
A) is derived from the sample. 
B) is determined by α and the type of test. 
C) is another name for the null hypothesis. 
D) is a dissenting view by scientific critics.

Question 11

The probability of rejecting a true null hypothesis is the significance level of the test.

Accepted Answer

A) True 
 B)False

Question 12

Dullco Manufacturing claims that its alkaline batteries last at least 40 hours on average in a certain type of portable CD player. But tests on a random sample of 18 batteries from a day's large production run showed a mean battery life of 37.8 hours with a standard deviation of 5.4 hours. To test DullCo's hypothesis, the test statistic is:

Accepted Answer

A) -1.980 
B) -1.728 
C) -2.101 
D) -1.960 
A) -1.980 
B) -1.728 
C) -2.101 
D) -1.960

Question 13

For a given sample size and α level, the Student's t value always exceeds the z value.

Accepted Answer

A) True 
 B)False

Question 14

A sample of 16 ATM transactions shows a mean transaction time of 67 seconds with a standard deviation of 12 seconds. Find the critical value to test whether the mean transaction time exceeds 60 seconds at α = .01.

Accepted Answer

A) 2.947 
B) 2.602 
C) 2.583 
D) 2.333 
A) 2.947 
B) 2.602 
C) 2.583 
D) 2.333

Question 15

Which of the following decisions could result in a Type II error for a test?

Accepted Answer

A) Reject the alternative hypothesis 
B) Reject the null hypothesis 
C) Fail to reject the null hypothesis 
D) Make no decision 
A) Reject the alternative hypothesis 
B) Reject the null hypothesis 
C) Fail to reject the null hypothesis 
D) Make no decision

Question 16

Dullco Manufacturing claims that its alkaline batteries last at least 40 hours on average in a certain type of portable CD player. But tests on a random sample of 18 batteries from a day's large production run showed a mean battery life of 37.8 hours with a standard deviation of 5.4 hours. To test DullCo's hypothesis, the p-value is:

Accepted Answer

A) slightly less than .05. 
B) exactly equal to .05. 
C) slightly greater than .05. 
D) uncertain without knowing α. 
A) slightly less than .05. 
B) exactly equal to .05. 
C) slightly greater than .05. 
D) uncertain without knowing α.

Question 17

Ajax Peanut Butter's quality control allows 2 percent of the jars to exceed the quality standard for insect fragments. A sample of 150 jars from the current day's production reveals that 30 exceed the quality standard for insect fragments. Which is incorrect?

Accepted Answer

A) Normality of p may safely be assumed in the hypothesis test. 
B) A right-tailed test would be appropriate. 
C) We strongly suspect that quality control standards aren't met. 
D) Type II error is more of a concern in this case than Type I error. 
A) Normality of p may safely be assumed in the hypothesis test. 
B) A right-tailed test would be appropriate. 
C) We strongly suspect that quality control standards aren't met. 
D) Type II error is more of a concern in this case than Type I error.

Question 18

In testing the hypotheses H0: π ≤ π0, H1: π > π0, we would use a:

Accepted Answer

A) two-tailed test. 
B) left-tailed test. 
C) right-tailed test. 
D) breathalyzer test. 
A) two-tailed test. 
B) left-tailed test. 
C) right-tailed test. 
D) breathalyzer test.

Question 19

Holding other factors constant, it is harder to reject the null hypothesis for a mean when conducting a two-tailed test rather than a one-tailed test.

Accepted Answer

A) True 
 B)False

Question 20

For a given null hypothesis and level of significance, the critical value for a two-tailed test is greater than the critical value for a one-tailed test.

Accepted Answer

A) True 
 B)False

Which of the following is incorrect?

Which is not true of p-values?

The researcher's null hypothesis is H₀: σ² = 420. A sample of n = 18 items yields a sample variance of s² = 512. The critical values of chi-square for a two-tailed test at α = .05 are:

In a right-tailed test, the null hypothesis is rejected when the value of the test statistic exceeds the critical value.

The critical value in a hypothesis test:

For a test of a mean, which of the following is incorrect?

The researcher's null hypothesis is H₀: σ² ≤ 22. A sample of n = 25 items yields a sample variance of s² = 28.5. The critical value of chi-square for a right-tailed test at α = .05 is:

The critical value in a hypothesis test:

The critical value in a hypothesis test:

The probability of rejecting a true null hypothesis is the significance level of the test.

For a given sample size and α level, the Student's t value always exceeds the z value.

A sample of 16 ATM transactions shows a mean transaction time of 67 seconds with a standard deviation of 12 seconds. Find the critical value to test whether the mean transaction time exceeds 60 seconds at α = .01.

Which of the following decisions could result in a Type II error for a test?

Ajax Peanut Butter's quality control allows 2 percent of the jars to exceed the quality standard for insect fragments. A sample of 150 jars from the current day's production reveals that 30 exceed the quality standard for insect fragments. Which is incorrect?

In testing the hypotheses H₀: π ≤ π₀, H₁: π > π₀, we would use a:

Holding other factors constant, it is harder to reject the null hypothesis for a mean when conducting a two-tailed test rather than a one-tailed test.

For a given null hypothesis and level of significance, the critical value for a two-tailed test is greater than the critical value for a one-tailed test.

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

Which of the following is incorrect?

Which is not true of p-values?

The researcher's null hypothesis is H0: σ2 = 420. A sample of n = 18 items yields a sample variance of s2 = 512. The critical values of chi-square for a two-tailed test at α = .05 are:

In a right-tailed test, the null hypothesis is rejected when the value of the test statistic exceeds the critical value.

The critical value in a hypothesis test:

For a test of a mean, which of the following is incorrect?

The researcher's null hypothesis is H0: σ2 ≤ 22. A sample of n = 25 items yields a sample variance of s2 = 28.5. The critical value of chi-square for a right-tailed test at α = .05 is:

The critical value in a hypothesis test:

The critical value in a hypothesis test:

The probability of rejecting a true null hypothesis is the significance level of the test.

For a given sample size and α level, the Student's t value always exceeds the z value.

A sample of 16 ATM transactions shows a mean transaction time of 67 seconds with a standard deviation of 12 seconds. Find the critical value to test whether the mean transaction time exceeds 60 seconds at α = .01.

Which of the following decisions could result in a Type II error for a test?

Ajax Peanut Butter's quality control allows 2 percent of the jars to exceed the quality standard for insect fragments. A sample of 150 jars from the current day's production reveals that 30 exceed the quality standard for insect fragments. Which is incorrect?

In testing the hypotheses H0: π ≤ π0, H1: π > π0, we would use a:

Holding other factors constant, it is harder to reject the null hypothesis for a mean when conducting a two-tailed test rather than a one-tailed test.

For a given null hypothesis and level of significance, the critical value for a two-tailed test is greater than the critical value for a one-tailed test.

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

The researcher's null hypothesis is H₀: σ² = 420. A sample of n = 18 items yields a sample variance of s² = 512. The critical values of chi-square for a two-tailed test at α = .05 are:

The researcher's null hypothesis is H₀: σ² ≤ 22. A sample of n = 25 items yields a sample variance of s² = 28.5. The critical value of chi-square for a right-tailed test at α = .05 is:

In testing the hypotheses H₀: π ≤ π₀, H₁: π > π₀, we would use a: