Question 1

Measures of proportion of variance are computed the same for all t tests.

Accepted Answer

A) True 
 B)False

Question 2

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 3

To compute a two-independent 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 pooled sample variance 
B) the pooled population variance 
C) the sample size for both samples 
D) the sample mean for both samples 
A) the pooled sample variance 
B) the pooled population variance 
C) the sample size for both samples 
D) the sample mean for both samples

Question 4

A researcher reports a significant effect in some population.If he computes both an eta-squared and an omega-squared effect size estimate,then which estimate will be the largest?

Accepted Answer

A) eta-squared 
B) omega-squared 
C) It depends on the sample size. 
D) It depends on the value of the t statistic. 
A) eta-squared 
B) omega-squared 
C) It depends on the sample size. 
D) It depends on the value of the t statistic.

Question 5

A researcher reports that the mean time it takes to complete an experimental task is 1.4±8.0 (M±SD)seconds.If the null hypothesis was that the mean equals 1.0,then what is the effect size for this test using estimated Cohen's d?

Accepted Answer

A) d = 0.05;small effect size 
B) d = 0.50;medium effect size 
C) d = 1.05;large effect size 
D) There is not enough information to answer this question. 
A) d = 0.05;small effect size 
B) d = 0.50;medium effect size 
C) d = 1.05;large effect size 
D) There is not enough information to answer this question.

Question 6

A researcher records the crying time (in minutes)of infants given oral administration of sucrose (n = 12)or tap water (n = 16)prior to a heel prick.The mean crying time in the sucrose group was 3.3±2.4 (M±SD)minutes;in the tap water group,it was 7.3±1.6 (M±SD)minutes.If the null hypothesis is that there is no difference in crying time,then what is the decision for this test?

Accepted Answer

A) Crying time was significantly reduced among infants given the water solution prior to a heel prick. 
B) Crying time was not reduced among infants given the sucrose solution prior to a heel prick. 
C) Crying time was significantly reduced among infants given the sucrose solution prior to a heel prick. 
D) Crying time was the same in both groups. 
A) Crying time was significantly reduced among infants given the water solution prior to a heel prick. 
B) Crying time was not reduced among infants given the sucrose solution prior to a heel prick. 
C) Crying time was significantly reduced among infants given the sucrose solution prior to a heel prick. 
D) Crying time was the same in both groups.

Question 7

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 8

The average response time to a bank robbery is about 9 minutes.A local community wants to improve on this time,so they implement advanced training seminars.They find that the new response time for a sample of 36 police officers is 8±4.2 (M±SD)minutes.Test whether this advanced training seminar reduced response time at a .05 level of significance.

Accepted Answer

A) This advanced training seminar significantly reduced response time,t(35)= 11.43,p  .05. 
D) There is not enough information to answer this question. 
A) This advanced training seminar significantly reduced response time,t(35)= 11.43,p  .05. 
D) There is not enough information to answer this question.

Question 9

If d = 0.28,then we conclude that mean scores in some population have shifted 0.28 standard deviations below the mean.

Accepted Answer

A) True 
 B)False

Question 10

A researcher computes a two-independent sample t test and finds that the result is undefined (the denominator is equal to 0).This happens when there is no difference between the two groups .

Accepted Answer

A) True 
 B)False

Question 11

A researcher has participants rate the likability of a sexually promiscuous person described in a vignette as being male (n = 20)or female (n = 12).The mean likability ratings in each group were 4.0.If the null hypothesis is that there is no difference in likability ratings,then do likability ratings differ at a .05 level of significance?

Accepted Answer

A) Yes,this result is significant,p < .05. 
B) No,this result is not significant,t(30)= 0. 
C) No,this result is not significant,t(30)= 1.00. 
D) There is not enough information to answer this question,because the variance in each sample is not given. 
A) Yes,this result is significant,p < .05. 
B) No,this result is not significant,t(30)= 0. 
C) No,this result is not significant,t(30)= 1.00. 
D) There is not enough information to answer this question,because the variance in each sample is not given.

Question 12

A two-independent sample t test is computed when mean differences are compared between two or more groups sampled from a population with an unknown variance.

Accepted Answer

A) True 
 B)False

Question 13

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 14

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 15

Which measure of effect size is most commonly reported with a t test?

Accepted Answer

A) eta-squared 
B) omega-squared 
C) t statistic 
D) Cohen's d 
A) eta-squared 
B) omega-squared 
C) t statistic 
D) Cohen's d

Question 16

As the degrees of freedom for a t test increase,the critical values for that test also increase.

Accepted Answer

A) True 
 B)False

Question 17

A researcher records differences in ratings of emotion among participants watching either a drama or a romance film.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.

Question 18

A one-sample t test will be t = 0 when the standard error was equal to 0.

Accepted Answer

A) True 
 B)False

Question 19

Cohen's d is a measure of proportion of variance.

Accepted Answer

A) True 
 B)False

Question 20

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.

Measures of proportion of variance are computed the same for all t tests.

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?

To compute a two-independent 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 a significant effect in some population.If he computes both an eta-squared and an omega-squared effect size estimate,then which estimate will be the largest?

A researcher reports that the mean time it takes to complete an experimental task is 1.4±8.0 (M±SD)seconds.If the null hypothesis was that the mean equals 1.0,then what is the effect size for this test using estimated Cohen's d?

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

If d = 0.28,then we conclude that mean scores in some population have shifted 0.28 standard deviations below the mean.

A researcher computes a two-independent sample t test and finds that the result is undefined (the denominator is equal to 0).This happens when there is no difference between the two groups .

A two-independent sample t test is computed when mean differences are compared between two or more groups sampled from a population with an unknown variance.

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

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?

Which measure of effect size is most commonly reported with a t test?

As the degrees of freedom for a t test increase,the critical values for that test also increase.

A researcher records differences in ratings of emotion among participants watching either a drama or a romance film.Assuming that the population variance is unknown,what type of t test is appropriate for this study?

A one-sample t test will be t = 0 when the standard error was equal to 0.

Cohen's d is a measure of proportion of variance.

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?

Introduction to Statistics

Summarizing Data: Frequency Distributions in

Summarizing Data: Central Tendency

Summarizing Data: Variability

Probability, Normal Distributions, and Z Scores

Characteristics of the Sample Mean

Hypothesis Testing: Significance, Effect Size, and Power

Testing Means: One-Sample T Test With Confidence Intervals

Testing Means: Related-Samples T Test With Confidence Intervals

One-Way Analysis of Variance: Between- Subjects and Within- Subjects Repeated- Measures Designs

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

Correlation and Linear Regression

Chi-Square Tests: Goodness of Fit and the Test for Independence

Nonparametric Tests for Ordinal Data: Understanding and Interpretation

Chi-Square Tests: Goodness-of-Fit and Independence

Understanding Regression Analysis

Understanding Correlation Coefficients in Statistical Analysis

Filters

Exam 9: Testing Means: Two- Independent-Sample T Test With Confidence Intervals

Measures of proportion of variance are computed the same for all t tests.

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?

To compute a two-independent 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 a significant effect in some population.If he computes both an eta-squared and an omega-squared effect size estimate,then which estimate will be the largest?

A researcher reports that the mean time it takes to complete an experimental task is 1.4±8.0 (M±SD)seconds.If the null hypothesis was that the mean equals 1.0,then what is the effect size for this test using estimated Cohen's d?

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

If d = 0.28,then we conclude that mean scores in some population have shifted 0.28 standard deviations below the mean.

A researcher computes a two-independent sample t test and finds that the result is undefined (the denominator is equal to 0).This happens when there is no difference between the two groups .

A two-independent sample t test is computed when mean differences are compared between two or more groups sampled from a population with an unknown variance.

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

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?

Which measure of effect size is most commonly reported with a t test?

As the degrees of freedom for a t test increase,the critical values for that test also increase.

A researcher records differences in ratings of emotion among participants watching either a drama or a romance film.Assuming that the population variance is unknown,what type of t test is appropriate for this study?

A one-sample t test will be t = 0 when the standard error was equal to 0.

Cohen's d is a measure of proportion of variance.

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?

Introduction to Statistics

Summarizing Data: Frequency Distributions in

Summarizing Data: Central Tendency

Summarizing Data: Variability

Probability, Normal Distributions, and Z Scores

Characteristics of the Sample Mean

Hypothesis Testing: Significance, Effect Size, and Power

Testing Means: One-Sample T Test With Confidence Intervals

Testing Means: Related-Samples T Test With Confidence Intervals

One-Way Analysis of Variance: Between- Subjects and Within- Subjects Repeated- Measures Designs

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

Correlation and Linear Regression

Chi-Square Tests: Goodness of Fit and the Test for Independence

Nonparametric Tests for Ordinal Data: Understanding and Interpretation

Chi-Square Tests: Goodness-of-Fit and Independence

Understanding Regression Analysis

Understanding Correlation Coefficients in Statistical Analysis

Filters