Question 1

In the t test for correlated groups, a directional H 1 may predict µ D > 0.

Accepted Answer

A) True 
 B)False

Question 2

The mean of the sampling distribution of   = _________.

Accepted Answer

A)  µ 
B)  0 
C)  1 
D)  µ 1 - µ 2 
A)  µ 
B)  0 
C)  1 
D)  µ 1 - µ 2

Question 3

If a test is a robust test,

Accepted Answer

A)  it is sensitive to its underlying mathematical assumptions 
B)  it doesn't estimate any population parameters 
C)  it is insensitive to its underlying mathematical assumptions 
D)  it often may be used despite violations of its underlying mathematical assumptions 
E)  it is insensitive to its underlying mathematical assumptions and it often may be used despite violations of its underlying mathematical assumptions 
A)  it is sensitive to its underlying mathematical assumptions 
B)  it doesn't estimate any population parameters 
C)  it is insensitive to its underlying mathematical assumptions 
D)  it often may be used despite violations of its underlying mathematical assumptions 
E)  it is insensitive to its underlying mathematical assumptions and it often may be used despite violations of its underlying mathematical assumptions

Question 4

The t test assumes that the independent variable affects either the mean of the dependent variable or the standard deviation, but not both.

Accepted Answer

A) True 
 B)False

Question 5

Define null-hypothesis approach.

Accepted Answer

The null-hypothesis approach is a fundam

Question 6

Based on your answer to problem 30, using a = .05 2 tail, what do you conclude about H 0?

Accepted Answer

A)  accept H 0 ; stress does not affect the menstrual cycle 
B)  retain H 0 ; we cannot conclude that stress affects the menstrual cycle 
C)  retain H 0 ; stress affects the menstrual cycle 
D)  reject H 0 ; stress affects the menstrual cycle 
A)  accept H 0 ; stress does not affect the menstrual cycle 
B)  retain H 0 ; we cannot conclude that stress affects the menstrual cycle 
C)  retain H 0 ; stress affects the menstrual cycle 
D)  reject H 0 ; stress affects the menstrual cycle

Question 7

Which of the following tests analyzes the difference between the means of two independent samples?

Accepted Answer

A)  correlated t test 
B)  t test for independent groups 
C)  sign test 
D)  all of these 
A)  correlated t test 
B)  t test for independent groups 
C)  sign test 
D)  all of these

Question 8

H1 cannot be true if   = 0 for a correlated groups design.

Accepted Answer

A) True 
 B)False

Question 9

The t test for correlated groups requires that _________.

Accepted Answer

A)  the sampling distribution of   is normally distributed 
B)  N ≥ 30 
C)  the population raw scores are normally distributed 
D)  the sampling distribution of   is normally is normally distributed 
A)  the sampling distribution of   is normally distributed 
B)  N ≥ 30 
C)  the population raw scores are normally distributed 
D)  the sampling distribution of   is normally is normally distributed

Question 10

A professor of women's studies is interested in determining if stress affects the menstrual cycle. Ten women are randomly sampled for an experiment and randomly divided into two groups. One of the groups is subjected to high stress for two months while the other lives in a relatively stress-free environment. The professor measures the menstrual cycle (in days) of each woman during the second month. The following data are obtained.   Construct the 95% confidence interval for ì 1 - ì 2. The 95 % confidence interval = _________.

Accepted Answer

A)  -10.712 - -3.688 
B)  -8.341 - 1.405 
C)  -9.264 - -2.627 
D)  -10.204 - -3.348 
A)  -10.712 - -3.688 
B)  -8.341 - 1.405 
C)  -9.264 - -2.627 
D)  -10.204 - -3.348

Question 11

In an independent groups design, if the independent variable has a real effect, µ 1 ≠µ 2 .

Accepted Answer

A) True 
 B)False

Question 12

If n 1 = n 2 and n is relatively large, then the t test is relatively robust against _________.

Accepted Answer

A)  violations of the assumptions of homogeneity of variance and normality 
B)  violations of random samples 
C)  traffic violations 
D)  violations by the forces of evil 
A)  violations of the assumptions of homogeneity of variance and normality 
B)  violations of random samples 
C)  traffic violations 
D)  violations by the forces of evil

Question 13

A professor of women's studies is interested in determining if stress affects the menstrual cycle. Ten women are randomly sampled for an experiment and randomly divided into two groups. One of the groups is subjected to high stress for two months while the other lives in a relatively stress-free environment. The professor measures the menstrual cycle (in days) of each woman during the second month. The following data are obtained.   Assume there is a real effect and estimate the size of the effect. _________.

Accepted Answer

A)  0.8102 
B)  0.6810 
C)  0.4322 
D)  0.5776 
A)  0.8102 
B)  0.6810 
C)  0.4322 
D)  0.5776

Question 14

In a t test for two independent samples, the unbiased estimate of the population variance is

Accepted Answer

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

Question 15

A health educator wants to evaluate the effect of a dental film on the frequency with which children brush their teeth. A random selection of 8 children are used for the experiment. First, a baseline of the number of times the children brush their teeth over a month's period is established. Next, the children are shown the dental film and again the number of teeth brushings are recorded for a month. The following data are recorded.   Assume there is a real effect and estimate the size of effect, using Cohens d. = _________.

Accepted Answer

A)  1.10 
B)  0.03 
C)  1.11 
D)  0.02 
A)  1.10 
B)  0.03 
C)  1.11 
D)  0.02

Question 16

In employing a correlated groups design, one possible drawback is _________.

Accepted Answer

A)  the increased number of statistical computations 
B)  random errors are likely to be greater 
C)  reduction in the degrees of freedom 
D)  none of these 
A)  the increased number of statistical computations 
B)  random errors are likely to be greater 
C)  reduction in the degrees of freedom 
D)  none of these

Question 17

A dog food manufacturer believes that he may have found a way to improve the taste of the dog food made by his company. To test the new process, the company recruited 12 dogs. The dogs were given the original food and the time required to eat a standard portion of the food was measured. Two days later the same dogs were fed the same quantity of the new formula and the time was measured again. The following times were recorded: It is assumed that faster eating represents greater preference for the product.

Accepted Answer

The answer of A dog food manufacturer believes that he...

Question 18

What are the variables that affect the power of the t test? How does increasing each variable affect power?

Accepted Answer

The power of a t-test is affected by sev

Question 19

The t test for independent groups is a robust test.

Accepted Answer

A) True 
 B)False

Question 20

Homogeneity of variance means that µ 1 = µ 2 .

Accepted Answer

A) True 
 B)False

In the t test for correlated groups, a directional H 1 may predict µ D > 0.

The mean of the sampling distribution of = _________.

If a test is a robust test,

The t test assumes that the independent variable affects either the mean of the dependent variable or the standard deviation, but not both.

Define null-hypothesis approach.

Based on your answer to problem 30, using a = .05 2 tail, what do you conclude about H ₀?

Which of the following tests analyzes the difference between the means of two independent samples?

H₁ cannot be true if = 0 for a correlated groups design.

The t test for correlated groups requires that _________.

In an independent groups design, if the independent variable has a real effect, µ 1 ≠µ 2 .

If n 1 = n 2 and n is relatively large, then the t test is relatively robust against _________.

In a t test for two independent samples, the unbiased estimate of the population variance is

In employing a correlated groups design, one possible drawback is _________.

What are the variables that affect the power of the t test? How does increasing each variable affect power?

The t test for independent groups is a robust test.

Homogeneity of variance means that µ 1 = µ 2 .

Statistics and Scientific Method

Basic Mathematical and Measurement Concepts

Frequency Distributions

Measures of Central Tendency and Variability

The Normal Curve and Standard Scores

Correlation

Linear Regression

Random Sampling and Probability

Binomial Distribution

Introduction to Hypothesis Testing: Using the Sign Test

Power

Sampling Distributions, Sampling Distribution of the Mean: the Normal Deviate Z Test

Students T Test for Single Samples

Introduction to the Analysis of Variance

Introduction to the Two-Way Analysis of Variance

Chi-Square and Other Nonparametric Tests

Filters

Exam 14: Students T Test for Correlated and Independent Groups

In the t test for correlated groups, a directional H 1 may predict µ D > 0.

The mean of the sampling distribution of = _________.

If a test is a robust test,

The t test assumes that the independent variable affects either the mean of the dependent variable or the standard deviation, but not both.

Define null-hypothesis approach.

Based on your answer to problem 30, using a = .05 2 tail, what do you conclude about H 0?

Which of the following tests analyzes the difference between the means of two independent samples?

H1 cannot be true if = 0 for a correlated groups design.

The t test for correlated groups requires that _________.

In an independent groups design, if the independent variable has a real effect, µ 1 ≠µ 2 .

If n 1 = n 2 and n is relatively large, then the t test is relatively robust against _________.

In a t test for two independent samples, the unbiased estimate of the population variance is

In employing a correlated groups design, one possible drawback is _________.

What are the variables that affect the power of the t test? How does increasing each variable affect power?

The t test for independent groups is a robust test.

Homogeneity of variance means that µ 1 = µ 2 .

Statistics and Scientific Method

Basic Mathematical and Measurement Concepts

Frequency Distributions

Measures of Central Tendency and Variability

The Normal Curve and Standard Scores

Correlation

Linear Regression

Random Sampling and Probability

Binomial Distribution

Introduction to Hypothesis Testing: Using the Sign Test

Power

Sampling Distributions, Sampling Distribution of the Mean: the Normal Deviate Z Test

Students T Test for Single Samples

Introduction to the Analysis of Variance

Introduction to the Two-Way Analysis of Variance

Chi-Square and Other Nonparametric Tests

Filters

Based on your answer to problem 30, using a = .05 2 tail, what do you conclude about H ₀?

H₁ cannot be true if = 0 for a correlated groups design.