Question 1

What is the null hypothesis of the above example?

Accepted Answer

A)  Prisoners are more aggressive than college students. 
B)  College students are more aggressive than prisoners. 
C)  There is no relationship between stress levels and groups. 
D)  Prisoners and college students are not different in aggression levels. 
A)  Prisoners are more aggressive than college students. 
B)  College students are more aggressive than prisoners. 
C)  There is no relationship between stress levels and groups. 
D)  Prisoners and college students are not different in aggression levels.

Question 2

If we built on Doob and Gross's study of horn-honking behavior to compare the time it takes for people to honk at an older car versus the time to honk at an expensive newer car, we could set it up as

Accepted Answer

A)  an independent sample design. 
B)  a repeated measures design. 
C)  neither a nor b 
D)  It could be designed either way, depending upon our needs. 
A)  an independent sample design. 
B)  a repeated measures design. 
C)  neither a nor b 
D)  It could be designed either way, depending upon our needs.

Question 3

In which of the following cases is it most useful to pool the variances?

Accepted Answer

A)  s12 = 7.3, N1 = 15 and s22 = 8.1, N2 = 15 
B)  s12 = 7.3, N1 = 15 and s22 = 52.3, N2 = 6 
C)  s12 = 8.4, N1 = 13 and s22 = 12.1, N2 = 19 
D)  none of the above 
A)  s12 = 7.3, N1 = 15 and s22 = 8.1, N2 = 15 
B)  s12 = 7.3, N1 = 15 and s22 = 52.3, N2 = 6 
C)  s12 = 8.4, N1 = 13 and s22 = 12.1, N2 = 19 
D)  none of the above

Question 4

Sample variances are always pooled when computing independent samples t-tests.

Accepted Answer

A) True 
 B)False

Question 5

In the anorexia example comparing Family Therapy and Control conditions the null hypothesis would be

Accepted Answer

A)  m FT = m C 
B)  m FT ≠ m C 
C)  m FT m C 
D)  m FT > m C 
A)  m FT = m C 
B)  m FT ≠ m C 
C)  m FT m C 
D)  m FT > m C

Question 6

When we have very unequal sample variances, we should

Accepted Answer

A)  check our work very carefully when we pool the variances. 
B)  not pool the variances. 
C)  average the variances, but not weight them with the degrees of freedom. 
D)  run some different analysis. 
A)  check our work very carefully when we pool the variances. 
B)  not pool the variances. 
C)  average the variances, but not weight them with the degrees of freedom. 
D)  run some different analysis.

Question 7

Which of the following would most likely NOT be independent samples?

Accepted Answer

A)  Group 1 contains wives and Group 2 contains their husbands. 
B)  Group 1 contains women and Group 2 contains men. 
C)  Group 1 contains dyslexic children and Group 2 contains non-dyslexic children. 
D)  Group 1 contains smokers and Group 2 contains nonsmokers. 
A)  Group 1 contains wives and Group 2 contains their husbands. 
B)  Group 1 contains women and Group 2 contains men. 
C)  Group 1 contains dyslexic children and Group 2 contains non-dyslexic children. 
D)  Group 1 contains smokers and Group 2 contains nonsmokers.

Question 8

The statistical test that compares two or more means is a(n)

Accepted Answer

A)  t-test. 
B)  z -score. 
C)  ANOVA. 
D)  correlation. 
A)  t-test. 
B)  z -score. 
C)  ANOVA. 
D)  correlation.

Question 9

We want to compare the scores of two different groups of people, those who are high in authoritarianism versus those who are low in authoritarianism, on a scale that measures leadership ability. What is the best statistical test to perform to see if the two groups are different from each other on this measure?

Accepted Answer

A)  paired samples t-test 
B)  t-test for independent groups 
C)  factorial ANOVA 
D)  one way ANOVA 
A)  paired samples t-test 
B)  t-test for independent groups 
C)  factorial ANOVA 
D)  one way ANOVA

Question 10

Indicate whether or not it would be appropriate to use pooled variances to calculate t given the following information. Explain your answers. 
a. s12 = 1.5, N1 = 30 and s22 = 8.5, N2 = 50 
b. s12 = 10, N1 = 40 and s22 = 15, N2 = 48

Accepted Answer

a. No, because the variance of

Question 11

Pooled variance is the sum of the variance from two samples.

Accepted Answer

A) True 
 B)False

Question 12

Using the conservative test in which variances were not pooled that was described in the text, on how many degrees of freedom would the t test on groups of 65 and 21 participants be based?

Accepted Answer

A)  65 - 1 = 64 df 
B)  21 - 1 = 20 df 
C)  65 + 21 - 2 = 84 df 
D)  (65 + 21) ÷ 2 = 43 df 
A)  65 - 1 = 64 df 
B)  21 - 1 = 20 df 
C)  65 + 21 - 2 = 84 df 
D)  (65 + 21) ÷ 2 = 43 df

Question 13

A group of children exposed to violence on television (N = 20) scored higher on a measure of aggression than a group of children who were not exposed to violence on television (N = 22). t = 1.25. What can you conclude?

Accepted Answer

There is not a significant dif

Question 14

In an independent samples t-test comparing the means of a sample of 25 and a sample of 30, the df = 53.

Accepted Answer

A) True 
 B)False

Question 15

A researcher was interested in examining the different levels of aggression shown by college students and prisoners with life sentences. Aggression was measured by surveys given during one session. Which analysis should the researcher perform on the mean aggression scores of the groups?

Accepted Answer

A)  related means t test 
B)  independent means t test 
C)  correlation 
D)  regression 
A)  related means t test 
B)  independent means t test 
C)  correlation 
D)  regression

Question 16

Explain an appropriate method to compare means from independent samples when the sample variances are heterogeneous.

Accepted Answer

When the assumption of homogeneity of va

Question 17

The variance sum law deals with

Accepted Answer

A)  the variance of the sum of two or more variables. 
B)  the variance of the difference of two or more variables. 
C)  the variance of any single variable. 
D)  both a) and b). 
A)  the variance of the sum of two or more variables. 
B)  the variance of the difference of two or more variables. 
C)  the variance of any single variable. 
D)  both a) and b).

Question 18

A political analyst wants to know if there are differences in how men and women are perceiving his candidate. In his sample, political party membership does not differ for males and females. Thus, gender and political party are confounded.

Accepted Answer

A) True 
 B)False

Question 19

The following data are taken from Chapter 14 and refer to a study of weight gain in treated and untreated girls suffering from anorexia.
 
Which of the following formula for t in this situation would be a correct one?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 20

In the previous example, how many df do we have?

Accepted Answer

A)  25 
B)  43 
C)  41 
D)  21.5 
A)  25 
B)  43 
C)  41 
D)  21.5

What is the null hypothesis of the above example?

If we built on Doob and Gross's study of horn-honking behavior to compare the time it takes for people to honk at an older car versus the time to honk at an expensive newer car, we could set it up as

In which of the following cases is it most useful to pool the variances?

Sample variances are always pooled when computing independent samples t-tests.

In the anorexia example comparing Family Therapy and Control conditions the null hypothesis would be

When we have very unequal sample variances, we should

Which of the following would most likely NOT be independent samples?

The statistical test that compares two or more means is a(n)

Indicate whether or not it would be appropriate to use pooled variances to calculate t given the following information. Explain your answers. a. s₁² = 1.5, N₁ = 30 and s₂² = 8.5, N₂ = 50 b. s₁² = 10, N₁ = 40 and s₂² = 15, N₂ = 48

Pooled variance is the sum of the variance from two samples.

Using the conservative test in which variances were not pooled that was described in the text, on how many degrees of freedom would the t test on groups of 65 and 21 participants be based?

A group of children exposed to violence on television (N = 20) scored higher on a measure of aggression than a group of children who were not exposed to violence on television (N = 22). t = 1.25. What can you conclude?

In an independent samples t-test comparing the means of a sample of 25 and a sample of 30, the df = 53.

A researcher was interested in examining the different levels of aggression shown by college students and prisoners with life sentences. Aggression was measured by surveys given during one session. Which analysis should the researcher perform on the mean aggression scores of the groups?

Explain an appropriate method to compare means from independent samples when the sample variances are heterogeneous.

The variance sum law deals with

A political analyst wants to know if there are differences in how men and women are perceiving his candidate. In his sample, political party membership does not differ for males and females. Thus, gender and political party are confounded.

The following data are taken from Chapter 14 and refer to a study of weight gain in treated and untreated girls suffering from anorexia. Which of the following formula for t in this situation would be a correct one?

In the previous example, how many df do we have?

Introduction

Basic Concepts

Displaying Data

Measures of Central Tendency

Measures of Variability

The Normal Distribution

Basic Concepts of Probability

Sampling Distributions and Hypothesis Testing

Correlation

Regression

Multiple Regression

Hypothesis Tests Applied to Means: One Sample

Hypothesis Tests Applied to Means: Two Related Samples

Power

One-Way Analysis of Variance

Factorial Analysis of Variance

Repeated-Measures Analysis of Variance

Chi-Square

Nonparametric and Resampling Statistical Tests

Meta-Analysis

Filters

Exam 14: Hypothesis Tests Applied to Means: Two Independent Samples

What is the null hypothesis of the above example?

If we built on Doob and Gross's study of horn-honking behavior to compare the time it takes for people to honk at an older car versus the time to honk at an expensive newer car, we could set it up as

In which of the following cases is it most useful to pool the variances?

Sample variances are always pooled when computing independent samples t-tests.

In the anorexia example comparing Family Therapy and Control conditions the null hypothesis would be

When we have very unequal sample variances, we should

Which of the following would most likely NOT be independent samples?

The statistical test that compares two or more means is a(n)

Indicate whether or not it would be appropriate to use pooled variances to calculate t given the following information. Explain your answers. a. s12 = 1.5, N1 = 30 and s22 = 8.5, N2 = 50 b. s12 = 10, N1 = 40 and s22 = 15, N2 = 48

Pooled variance is the sum of the variance from two samples.

Using the conservative test in which variances were not pooled that was described in the text, on how many degrees of freedom would the t test on groups of 65 and 21 participants be based?

A group of children exposed to violence on television (N = 20) scored higher on a measure of aggression than a group of children who were not exposed to violence on television (N = 22). t = 1.25. What can you conclude?

In an independent samples t-test comparing the means of a sample of 25 and a sample of 30, the df = 53.

A researcher was interested in examining the different levels of aggression shown by college students and prisoners with life sentences. Aggression was measured by surveys given during one session. Which analysis should the researcher perform on the mean aggression scores of the groups?

Explain an appropriate method to compare means from independent samples when the sample variances are heterogeneous.

The variance sum law deals with

A political analyst wants to know if there are differences in how men and women are perceiving his candidate. In his sample, political party membership does not differ for males and females. Thus, gender and political party are confounded.

The following data are taken from Chapter 14 and refer to a study of weight gain in treated and untreated girls suffering from anorexia. Which of the following formula for t in this situation would be a correct one?

In the previous example, how many df do we have?

Introduction

Basic Concepts

Displaying Data

Measures of Central Tendency

Measures of Variability

The Normal Distribution

Basic Concepts of Probability

Sampling Distributions and Hypothesis Testing

Correlation

Regression

Multiple Regression

Hypothesis Tests Applied to Means: One Sample

Hypothesis Tests Applied to Means: Two Related Samples

Power

One-Way Analysis of Variance

Factorial Analysis of Variance

Repeated-Measures Analysis of Variance

Chi-Square

Nonparametric and Resampling Statistical Tests

Meta-Analysis

Filters

Indicate whether or not it would be appropriate to use pooled variances to calculate t given the following information. Explain your answers. a. s₁² = 1.5, N₁ = 30 and s₂² = 8.5, N₂ = 50 b. s₁² = 10, N₁ = 40 and s₂² = 15, N₂ = 48