Question 1

What does it mean when the null hypothesis is rejected?

Accepted Answer

A)  The two groups are proven to be different. 
B)  Differences between means are truly different. 
C)  Observed mean differences are attributable to chance. 
D)  The probability that the null hypothesis is true is small. 
A)  The two groups are proven to be different. 
B)  Differences between means are truly different. 
C)  Observed mean differences are attributable to chance. 
D)  The probability that the null hypothesis is true is small. D

Question 2

In a pre-post design with 10 subjects, which t-test should be used, and what are the degrees of freedom?

Accepted Answer

A)  Independent (t-test) 18 (df) 
B)  Independent (t-test) 9 (df) 
C)  Dependent (t-test) 18 (df) 
D)  Dependent (t-test) 9 (df) 
A)  Independent (t-test) 18 (df) 
B)  Independent (t-test) 9 (df) 
C)  Dependent (t-test) 18 (df) 
D)  Dependent (t-test) 9 (df) D

Question 3

Fifteen sets of identical twins are the subjects in a drug experiment. One twin receives the treatment, and the other twin receives a placebo. What type of t-test should be conducted?

Accepted Answer

A)  Dependent t-test 
B)  Independent t-test 
C)  Need more information 
A)  Dependent t-test 
B)  Independent t-test 
C)  Need more information A

Question 4

What happens to the calculated t-ratio as the sample size increases?

Accepted Answer

A)  It increases 
B)  It decreases 
C)  It depends on the size of the differences between means 
D)  None of the above is accurate 
A)  It increases 
B)  It decreases 
C)  It depends on the size of the differences between means 
D)  None of the above is accurate

Question 5

What happens to the t-ratio as the difference between compared means decreases?

Accepted Answer

A)  It increases 
B)  It decreases 
C)  It depends on the sample sizes 
D)  It depends on the degrees of freedom 
A)  It increases 
B)  It decreases 
C)  It depends on the sample sizes 
D)  It depends on the degrees of freedom

Question 6

There are 30 subjects in each of the treatment and control groups. Which type of t-test should be conducted?

Accepted Answer

A)  Dependent t-test 
B)  Independent t-test 
C)  Need more information 
A)  Dependent t-test 
B)  Independent t-test 
C)  Need more information

Question 7

Which of the following is true for a given level of confidence?

Accepted Answer

A)  As sample size increases, the value of the critical t-ratio decreases. 
B)  As degrees of freedom increase, the value of the critical t-ratio decreases. 
C)  Both A and B are correct. 
D)  Neither A nor B is correct. 
A)  As sample size increases, the value of the critical t-ratio decreases. 
B)  As degrees of freedom increase, the value of the critical t-ratio decreases. 
C)  Both A and B are correct. 
D)  Neither A nor B is correct.

Question 8

What is the critical t-ratio value for a two-tailed test associated with an extremely large sample size at a 95% confidence level?

Accepted Answer

A)  2.58 
B)  1.96 
C)  1.65 
D)  Need more information 
A)  2.58 
B)  1.96 
C)  1.65 
D)  Need more information

Question 9

Which of the following t-ratios could not possibly be statistically significant at the 99% confidence level?

Accepted Answer

A)  3.00 
B)  2.80 
C)  2.60 
D)  2.50 
A)  3.00 
B)  2.80 
C)  2.60 
D)  2.50

Question 10

Under what condition are the independent and dependent t-tests identical?

Accepted Answer

A)  When the correlation between the two sets of scores is 1.0 
B)  When the correlation between the two sets of scores is -1.0 
C)  When the correlation between the two sets of scores is 0 
D)  Never 
A)  When the correlation between the two sets of scores is 1.0 
B)  When the correlation between the two sets of scores is -1.0 
C)  When the correlation between the two sets of scores is 0 
D)  Never

Question 11

Results are said to be statistically significant when the probability that the differences between means is attributable to chance is which of the following?

Accepted Answer

A)  High 
B)  Low 
C)  Zero 
D)  None of the above 
A)  High 
B)  Low 
C)  Zero 
D)  None of the above

Question 12

Which of the following terms is NOT associated with a DEPENDENT t-test?

Accepted Answer

A)  Between-subjects comparison 
B)  Matched subjects 
C)  Repeated measures 
D)  Within-subjects comparison 
A)  Between-subjects comparison 
B)  Matched subjects 
C)  Repeated measures 
D)  Within-subjects comparison

Question 13

What happens to the critical t-ratio as the sample size increases?

Accepted Answer

A)  It increases 
B)  It decreases 
C)  It depends on the size of the differences between means 
D)  None of the above is accurate 
A)  It increases 
B)  It decreases 
C)  It depends on the size of the differences between means 
D)  None of the above is accurate

Question 14

What happens to the t-ratio as the difference between compared means increases?

Accepted Answer

A)  It increases 
B)  It decreases 
C)  It depends on the sample sizes 
D)  It depends on the degrees of freedom 
A)  It increases 
B)  It decreases 
C)  It depends on the sample sizes 
D)  It depends on the degrees of freedom

Question 15

Which of the following terms is associated with an INDEPENDENT t-test?

Accepted Answer

A)  Within-subjects comparison 
B)  Matched subjects 
C)  Repeated measures 
D)  Between-subjects comparison 
A)  Within-subjects comparison 
B)  Matched subjects 
C)  Repeated measures 
D)  Between-subjects comparison

Question 16

What are the degrees of freedom in an independent t-test when 40 people are in each of the treatment and control groups?

Accepted Answer

A)  39 
B)  40 
C)  78 
D)  80 
A)  39 
B)  40 
C)  78 
D)  80

Question 17

Fifteen sets of identical twins are the subjects in a drug experiment. One twin receives the treatment, and the other twin receives a placebo. What are the degrees of freedom for the appropriate t-test?

Accepted Answer

A)  14 
B)  15 
C)  28 
D)  29 
E)  30 
A)  14 
B)  15 
C)  28 
D)  29 
E)  30

What does it mean when the null hypothesis is rejected?

In a pre-post design with 10 subjects, which t-test should be used, and what are the degrees of freedom?

Fifteen sets of identical twins are the subjects in a drug experiment. One twin receives the treatment, and the other twin receives a placebo. What type of t-test should be conducted?

What happens to the calculated t-ratio as the sample size increases?

What happens to the t-ratio as the difference between compared means decreases?

There are 30 subjects in each of the treatment and control groups. Which type of t-test should be conducted?

Which of the following is true for a given level of confidence?

What is the critical t-ratio value for a two-tailed test associated with an extremely large sample size at a 95% confidence level?

Which of the following t-ratios could not possibly be statistically significant at the 99% confidence level?

Under what condition are the independent and dependent t-tests identical?

Results are said to be statistically significant when the probability that the differences between means is attributable to chance is which of the following?

Which of the following terms is NOT associated with a DEPENDENT t-test?

What happens to the critical t-ratio as the sample size increases?

What happens to the t-ratio as the difference between compared means increases?

Which of the following terms is associated with an INDEPENDENT t-test?

What are the degrees of freedom in an independent t-test when 40 people are in each of the treatment and control groups?

Fifteen sets of identical twins are the subjects in a drug experiment. One twin receives the treatment, and the other twin receives a placebo. What are the degrees of freedom for the appropriate t-test?

Research Methods

Introduction to Measurement and Statistics

Descriptive Statistics

The Normal Curve and Standard Scores

Correlation and Regression

Introduction to Inferential Statistics

Issues in Inferential Statistics

One-Way Between-Groups Anova

One-Way Within-Groups Anova

Factorial Anova

Multivariate Anova Manova

Advanced Statistics

Nonparametric Statistics

Filters

Exam 7: Two-Sample T-Test

What does it mean when the null hypothesis is rejected?

In a pre-post design with 10 subjects, which t-test should be used, and what are the degrees of freedom?

Fifteen sets of identical twins are the subjects in a drug experiment. One twin receives the treatment, and the other twin receives a placebo. What type of t-test should be conducted?

What happens to the calculated t-ratio as the sample size increases?

What happens to the t-ratio as the difference between compared means decreases?

There are 30 subjects in each of the treatment and control groups. Which type of t-test should be conducted?

Which of the following is true for a given level of confidence?

What is the critical t-ratio value for a two-tailed test associated with an extremely large sample size at a 95% confidence level?

Which of the following t-ratios could not possibly be statistically significant at the 99% confidence level?

Under what condition are the independent and dependent t-tests identical?

Results are said to be statistically significant when the probability that the differences between means is attributable to chance is which of the following?

Which of the following terms is NOT associated with a DEPENDENT t-test?

What happens to the critical t-ratio as the sample size increases?

What happens to the t-ratio as the difference between compared means increases?

Which of the following terms is associated with an INDEPENDENT t-test?

What are the degrees of freedom in an independent t-test when 40 people are in each of the treatment and control groups?

Fifteen sets of identical twins are the subjects in a drug experiment. One twin receives the treatment, and the other twin receives a placebo. What are the degrees of freedom for the appropriate t-test?

Research Methods

Introduction to Measurement and Statistics

Descriptive Statistics

The Normal Curve and Standard Scores

Correlation and Regression

Introduction to Inferential Statistics

Issues in Inferential Statistics

One-Way Between-Groups Anova

One-Way Within-Groups Anova

Factorial Anova

Multivariate Anova Manova

Advanced Statistics

Nonparametric Statistics

Filters