Question 1

Is a one-sample t test reported differently for one-tailed and two-tailed tests?

Accepted Answer

A)  No, the same values are reported. 
B)  It depends on whether the results were significant. 
C)  Yes, only significant results for a two-tailed test are reported. 
D)  It can be reported differently when the effect size is large. 
A)  No, the same values are reported. 
B)  It depends on whether the results were significant. 
C)  Yes, only significant results for a two-tailed test are reported. 
D)  It can be reported differently when the effect size is large. A

Question 2

A key difference between a t statistic and a z statistic is that the standard error is ______ to compute a t statistic.

Accepted Answer

A)  removed 
B)  replaced 
C)  estimated 
D)  placed in the numerator 
A)  removed 
B)  replaced 
C)  estimated 
D)  placed in the numerator C

Question 3

As a requirement for the t test,researchers compute any type of t test with samples selected from populations in which

Accepted Answer

A)  the population variance is known. 
B)  the population size is very large. 
C)  the population variance is unknown. 
D)  the population is the same size as the sample. 
A)  the population variance is known. 
B)  the population size is very large. 
C)  the population variance is unknown. 
D)  the population is the same size as the sample. C

Question 4

The critical values are reported with the test statistic of a one-sample and a two-independent-sample t test using APA format.

Accepted Answer

A) True 
 B)False

Question 5

A t distribution with infinite degrees of freedom is a z distribution.

Accepted Answer

A) True 
 B)False

Question 6

Two researchers (A and B)compute a one-sample t test.For both tests,the standard error is the same,but the mean difference between the sample and value stated in the null hypothesis is smaller for Researcher A.Which test is more likely to result in a decision to reject the null hypothesis?

Accepted Answer

A)  Researcher A. 
B)  Researcher B. 
C)  The likelihood is the same for both researchers. 
D)  There is not enough information to answer this question. 
A)  Researcher A. 
B)  Researcher B. 
C)  The likelihood is the same for both researchers. 
D)  There is not enough information to answer this question.

Question 7

A researcher conducts two t tests.Test 1 is a one-tailed test with a smaller sample size at a .05 level of significance.Test 2 is a one-tailed test with a larger sample size at a .05 level of significance.What do you know about the critical values for each test?

Accepted Answer

A)  Test 1 is associated with smaller critical values. 
B)  Test 2 is associated with smaller critical values. 
C)  Each test is associated with the same critical values. 
D)  It depends; there is not enough information to answer this question. 
A)  Test 1 is associated with smaller critical values. 
B)  Test 2 is associated with smaller critical values. 
C)  Each test is associated with the same critical values. 
D)  It depends; there is not enough information to answer this question.

Question 8

When the proportion of variance explained by some treatment is larger than 0.25,we conclude that there is a large effect in the population.

Accepted Answer

A) True 
 B)False

Question 9

A professor compares final exam scores in his psychology class to final exam grades in another comparable professor's class.Assuming that the population variance of exam scores is unknown,what type of t test is appropriate for analyzing differences between these classes?

Accepted Answer

A)  one-sample t test 
B)  two-independent-sample t test 
C)  There is not enough information to answer this question. 
A)  one-sample t test 
B)  two-independent-sample t test 
C)  There is not enough information to answer this question.

Question 10

Which of the following is an assumption for the two-independent-sample t test,but not the one-sample t test?

Accepted Answer

A)  normality 
B)  random sampling 
C)  independence 
D)  equal variances 
A)  normality 
B)  random sampling 
C)  independence 
D)  equal variances

Question 11

A researcher conducts two t tests.Test 1 is a two-tailed test with a smaller sample size at a .05 level of significance.Test 2 is a two-tailed test with a larger sample size at a .05 level of significance.What do you know about the degrees of freedom for each test?

Accepted Answer

A)  Test 1 is associated with larger degrees of freedom. 
B)  Test 2 is associated with larger degrees of freedom. 
C)  Each test is associated with the same degrees of freedom. 
D)  It depends; there is not enough information to answer this question. 
A)  Test 1 is associated with larger degrees of freedom. 
B)  Test 2 is associated with larger degrees of freedom. 
C)  Each test is associated with the same degrees of freedom. 
D)  It depends; there is not enough information to answer this question.

Question 12

When scores are measured in a single group,the sample standard deviation is used as an estimate of the population standard deviation in the effect size formula for estimated Cohen's d.

Accepted Answer

A) True 
 B)False

Question 13

It is most appropriate to report effect size with a significant result.Why is it generally inappropriate to report effect size with nonsignificant results?

Accepted Answer

A)  Because insignificant results will always have an effect size equal to 0. 
B)  Because insignificant results indicate that an effect size is also not significant. 
C)  Because it makes little sense to report the size of an effect that you just concluded doesn't exist. 
D)  Because the probability of the size of an effect varies depending on the significance of the effect size measure. 
A)  Because insignificant results will always have an effect size equal to 0. 
B)  Because insignificant results indicate that an effect size is also not significant. 
C)  Because it makes little sense to report the size of an effect that you just concluded doesn't exist. 
D)  Because the probability of the size of an effect varies depending on the significance of the effect size measure.

Question 14

When the difference between two groups is compared,the pooled standard deviation is used as an estimate for the population standard deviation in the effect size formula for estimated Cohen's d.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following summarizes a t test that was significant and associated with a large effect size?

Accepted Answer

A) t(22) = 3.02, p .05, d = .20 C) t(60) = 1.76, p > .05, d = .45 D) t(12) = 2.95, p < .05, d = .82 A) t(22) = 3.02, p .05, d = .20 C) t(60) = 1.76, p > .05, d = .45 D) t(12) = 2.95, p < .05, d = .82

Question 16

To compute a one-sample t test,a researcher has to know many values.Which of the following is NOT a value that the researcher must know to compute this test?

Accepted Answer

A)  The estimated standard error must be known. 
B)  The population variance must be known. 
C)  The sample size must be known. 
D)  The sample mean and sample variance must be known. 
A)  The estimated standard error must be known. 
B)  The population variance must be known. 
C)  The sample size must be known. 
D)  The sample mean and sample variance must be known.

Question 17

A researcher reports the following result for a two-tailed test at a .05 level of significance,t(20)= 2.010,and correctly decides to reject the null hypothesis.

Accepted Answer

A) True 
 B)False

Question 18

A researcher selects a sample of 32 participants who are assigned to participate in a study with one group.What are the degrees of freedom for this test?

Accepted Answer

A)  32 
B)  30 
C)  31 
D)  There is not enough information to answer this question. 
A)  32 
B)  30 
C)  31 
D)  There is not enough information to answer this question.

Question 19

A t test is associated with n - 1 degrees of freedom.

Accepted Answer

A) True 
 B)False

Question 20

A researcher conducts a study measuring differences in brain activity among rats placed on either a continuous or intermittent reward schedule.Assuming that the population variance is unknown,what type of t test is appropriate for this study?

Accepted Answer

A)  one-sample t test 
B)  two-independent-sample t test 
C)  There is not enough information to answer this question. 
A)  one-sample t test 
B)  two-independent-sample t test 
C)  There is not enough information to answer this question.

Is a one-sample t test reported differently for one-tailed and two-tailed tests?

A key difference between a t statistic and a z statistic is that the standard error is ______ to compute a t statistic.

As a requirement for the t test,researchers compute any type of t test with samples selected from populations in which

The critical values are reported with the test statistic of a one-sample and a two-independent-sample t test using APA format.

A t distribution with infinite degrees of freedom is a z distribution.

Two researchers (A and B)compute a one-sample t test.For both tests,the standard error is the same,but the mean difference between the sample and value stated in the null hypothesis is smaller for Researcher A.Which test is more likely to result in a decision to reject the null hypothesis?

A researcher conducts two t tests.Test 1 is a one-tailed test with a smaller sample size at a .05 level of significance.Test 2 is a one-tailed test with a larger sample size at a .05 level of significance.What do you know about the critical values for each test?

When the proportion of variance explained by some treatment is larger than 0.25,we conclude that there is a large effect in the population.

A professor compares final exam scores in his psychology class to final exam grades in another comparable professor's class.Assuming that the population variance of exam scores is unknown,what type of t test is appropriate for analyzing differences between these classes?

Which of the following is an assumption for the two-independent-sample t test,but not the one-sample t test?

A researcher conducts two t tests.Test 1 is a two-tailed test with a smaller sample size at a .05 level of significance.Test 2 is a two-tailed test with a larger sample size at a .05 level of significance.What do you know about the degrees of freedom for each test?

When scores are measured in a single group,the sample standard deviation is used as an estimate of the population standard deviation in the effect size formula for estimated Cohen's d.

It is most appropriate to report effect size with a significant result.Why is it generally inappropriate to report effect size with nonsignificant results?

When the difference between two groups is compared,the pooled standard deviation is used as an estimate for the population standard deviation in the effect size formula for estimated Cohen's d.

Which of the following summarizes a t test that was significant and associated with a large effect size?

To compute a one-sample t test,a researcher has to know many values.Which of the following is NOT a value that the researcher must know to compute this test?

A researcher reports the following result for a two-tailed test at a .05 level of significance,t(20)= 2.010,and correctly decides to reject the null hypothesis.

A researcher selects a sample of 32 participants who are assigned to participate in a study with one group.What are the degrees of freedom for this test?

A t test is associated with n - 1 degrees of freedom.

A researcher conducts a study measuring differences in brain activity among rats placed on either a continuous or intermittent reward schedule.Assuming that the population variance is unknown,what type of t test is appropriate for this study?

Introduction to Statistics

Summarizing Data: Frequency Distributions in Tables and Graphs

Summarizing Data: Central Tendency

Summarizing Data: Variability

Probability

Probability, normal Distributions, and Z Scores

Probability and Sampling Distributions

Hypothesis Testing: Significance,effect Size,and Power

Testing Means: Truehe Related-Samples T Test

Estimation and Confidence Intervals

Analysis of Variance: One-Way Between-Subjects Design

Analysis of Variance: One-Way Within-Subjects Repeated-Measuresdesign

Analysis of Variance: Two-Way Between-Subjects Factorial Design

Correlation

Linear Regression and Multiple Regression

Nonparametric Tests: Chi-Square Tests

Nonparametric Tests: Tests for Ordinal Data

Filters

Exam 9: Testing Means: One-Sample and Two-Independent-Sample T Tests

Is a one-sample t test reported differently for one-tailed and two-tailed tests?

A key difference between a t statistic and a z statistic is that the standard error is ______ to compute a t statistic.

As a requirement for the t test,researchers compute any type of t test with samples selected from populations in which

The critical values are reported with the test statistic of a one-sample and a two-independent-sample t test using APA format.

A t distribution with infinite degrees of freedom is a z distribution.

Two researchers (A and B)compute a one-sample t test.For both tests,the standard error is the same,but the mean difference between the sample and value stated in the null hypothesis is smaller for Researcher A.Which test is more likely to result in a decision to reject the null hypothesis?

A researcher conducts two t tests.Test 1 is a one-tailed test with a smaller sample size at a .05 level of significance.Test 2 is a one-tailed test with a larger sample size at a .05 level of significance.What do you know about the critical values for each test?

When the proportion of variance explained by some treatment is larger than 0.25,we conclude that there is a large effect in the population.

A professor compares final exam scores in his psychology class to final exam grades in another comparable professor's class.Assuming that the population variance of exam scores is unknown,what type of t test is appropriate for analyzing differences between these classes?

Which of the following is an assumption for the two-independent-sample t test,but not the one-sample t test?

A researcher conducts two t tests.Test 1 is a two-tailed test with a smaller sample size at a .05 level of significance.Test 2 is a two-tailed test with a larger sample size at a .05 level of significance.What do you know about the degrees of freedom for each test?

When scores are measured in a single group,the sample standard deviation is used as an estimate of the population standard deviation in the effect size formula for estimated Cohen's d.

It is most appropriate to report effect size with a significant result.Why is it generally inappropriate to report effect size with nonsignificant results?

When the difference between two groups is compared,the pooled standard deviation is used as an estimate for the population standard deviation in the effect size formula for estimated Cohen's d.

Which of the following summarizes a t test that was significant and associated with a large effect size?

To compute a one-sample t test,a researcher has to know many values.Which of the following is NOT a value that the researcher must know to compute this test?

A researcher reports the following result for a two-tailed test at a .05 level of significance,t(20)= 2.010,and correctly decides to reject the null hypothesis.

A researcher selects a sample of 32 participants who are assigned to participate in a study with one group.What are the degrees of freedom for this test?

A t test is associated with n - 1 degrees of freedom.

A researcher conducts a study measuring differences in brain activity among rats placed on either a continuous or intermittent reward schedule.Assuming that the population variance is unknown,what type of t test is appropriate for this study?

Introduction to Statistics

Summarizing Data: Frequency Distributions in Tables and Graphs

Summarizing Data: Central Tendency

Summarizing Data: Variability

Probability

Probability, normal Distributions, and Z Scores

Probability and Sampling Distributions

Hypothesis Testing: Significance,effect Size,and Power

Testing Means: Truehe Related-Samples T Test

Estimation and Confidence Intervals

Analysis of Variance: One-Way Between-Subjects Design

Analysis of Variance: One-Way Within-Subjects Repeated-Measuresdesign

Analysis of Variance: Two-Way Between-Subjects Factorial Design

Correlation

Linear Regression and Multiple Regression

Nonparametric Tests: Chi-Square Tests

Nonparametric Tests: Tests for Ordinal Data

Filters