Question 1

Which of the techniques listed below are statistical methods that require few assumptions, if any, about the population distribution?

Accepted Answer

A)  parametric techniques 
B)  nonparametric techniques 
C)  free agent techniques 
D)  general techniques

Question 2

One of the required conditions of the sign test is that the number of non-zero differences n must be greater than or equal to 30.

Accepted Answer

A) True 
 B)False

Question 3

The z-test approximation to the Wilcoxon signed-rank sum test is used whenever the number of non-zero differences is at least 50.

Accepted Answer

A) True 
 B)False

Question 4

Using a nonparametric test when we could employ a parametric test can be less efficient because a nonparametric test often tends to ignore available sample information; for example, by focusing only on the directions rather than the sizes of observed differences.

Accepted Answer

A) True 
 B)False

Question 5

Which test is the nonparametric counterpart of the randomized block model of the analysis of variance?

Accepted Answer

A)  the Kruskal-Wallis test 
B)  the Friedman test 
C)  the Wilcoxon rank sum test 
D)  the Wilcoxon signed-rank sum test

Question 6

The Kruskal-Wallis test can be used to test for a difference between two populations. It will produce the same outcome as the two-tailed Wilcoxon rank sum test.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following statements is NOT a property of the Spearman's rank correlation coefficient?

Accepted Answer

A)  It is the test statistic used in Spearmen's rank correlation test. 
B)  It can take on values only between 0 and +1. 
C)  Positive values near +1 point to a monotonically increasing relationship between the two variables. 
D)  It specifies hypotheses in terms of population distributions rather than parameters.

Question 8

In a Kruskal-Wallis test, there are three samples and the value of the test statistic is calculated as H = 7.378. Then the p-value of the test is 0.025.

Accepted Answer

A) True 
 B)False

Question 9

Consider the following two independent samples:  Given this information, what is the value of the test statistic for a left-tailed Wilcoxon rank sum test?

Accepted Answer

A)  6 
B)  20 
C)  35 
D)  55

Question 10

The Kruskal-Wallis H test is an extension of the Wilcoxon rank sum test from two to more than two statistical populations.

Accepted Answer

A) True 
 B)False

Question 11

The population Spearman correlation coefficient is labelled  , and the sample statistic used to estimate its value is labelled  .

Accepted Answer

A) True 
 B)False

Question 12

The Kruskal-Wallis test is applied to compare two or more populations when the samples are independent and the data are either ordinal or interval but not normal.

Accepted Answer

A) True 
 B)False

Question 13

What are inferential procedures that are free from restrictive assumptions about the sampled populations?

Accepted Answer

A)  distribution-free tests (because no assumption about the nature of the population distribution is being made) 
B)  distribution-free tests (because no assumption about the nature of the sampling distributions of test statistics is being made) 
C)  parametric tests 
D)  general tests

Question 14

A parametric test is a hypothesis test that depends on certain specific assumptions about the probability distribution of population values or the sizes of population parameters.

Accepted Answer

A) True 
 B)False

Question 15

In a Kruskal-Wallis test, there are four samples and the value of the test statistic is calculated as H = 8.79. Under these conditions, which of the following is the most accurate statement that can be made about the p-value?

Accepted Answer

A)  It is greater than 0.10. 
B)  It is greater than 0.05 but smaller than 0.10. 
C)  It is greater than 0.05. 
D)  It is greater than 0.025 but smaller than 0.05.

Question 16

Which of the following statements correctly describes the sign test?

Accepted Answer

A)  It often uses the directions of differences observed in matched pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another. 
B)  It is often used to determine whether a sample comes from a population with a specified median. 
C)  Both (a) and (b). 
D)  Neither (a) nor (b).

Question 17

To determine if a relationship exists between two variables, the hypotheses to be tested are  , where  is the Spearman rank correlation coefficient.

Accepted Answer

A) True 
 B)False

Question 18

A two-sample t test with independent samples corresponds to which of the following tests?

Accepted Answer

A)  a sign test 
B)  a Wilcoxon rank sum test 
C)  a Wilcoxon signed-rank test e 
D)  a Friedman test for randomized block design

Question 19

A Wilcoxon rank sum test for comparing two populations involves two independent samples of sizes 15 and 20. If the value of non-standardized test statistic is T = 225, then the value of the standardized test statistic is z = -1.50.

Accepted Answer

A) True 
 B)False

Question 20

The Wilcoxon signed-rank test statistic is approximately normally distributed whenever the sample sizes are larger than or equal to which of the following values?

Accepted Answer

A)  10 
B)  20 
C)  25 
D)  35

Exam 15: A:nonparametric Statistics

Which of the techniques listed below are statistical methods that require few assumptions, if any, about the population distribution?

One of the required conditions of the sign test is that the number of non-zero differences n must be greater than or equal to 30.

The z-test approximation to the Wilcoxon signed-rank sum test is used whenever the number of non-zero differences is at least 50.

Using a nonparametric test when we could employ a parametric test can be less efficient because a nonparametric test often tends to ignore available sample information; for example, by focusing only on the directions rather than the sizes of observed differences.

Which test is the nonparametric counterpart of the randomized block model of the analysis of variance?

The Kruskal-Wallis test can be used to test for a difference between two populations. It will produce the same outcome as the two-tailed Wilcoxon rank sum test.

Which of the following statements is NOT a property of the Spearman's rank correlation coefficient?

In a Kruskal-Wallis test, there are three samples and the value of the test statistic is calculated as H = 7.378. Then the p-value of the test is 0.025.

Consider the following two independent samples: Given this information, what is the value of the test statistic for a left-tailed Wilcoxon rank sum test?

The Kruskal-Wallis H test is an extension of the Wilcoxon rank sum test from two to more than two statistical populations.

The population Spearman correlation coefficient is labelled , and the sample statistic used to estimate its value is labelled .

The Kruskal-Wallis test is applied to compare two or more populations when the samples are independent and the data are either ordinal or interval but not normal.

What are inferential procedures that are free from restrictive assumptions about the sampled populations?

A parametric test is a hypothesis test that depends on certain specific assumptions about the probability distribution of population values or the sizes of population parameters.

In a Kruskal-Wallis test, there are four samples and the value of the test statistic is calculated as H = 8.79. Under these conditions, which of the following is the most accurate statement that can be made about the p-value?

Which of the following statements correctly describes the sign test?

To determine if a relationship exists between two variables, the hypotheses to be tested are , where is the Spearman rank correlation coefficient.

A two-sample t test with independent samples corresponds to which of the following tests?

A Wilcoxon rank sum test for comparing two populations involves two independent samples of sizes 15 and 20. If the value of non-standardized test statistic is T = 225, then the value of the standardized test statistic is z = -1.50.

The Wilcoxon signed-rank test statistic is approximately normally distributed whenever the sample sizes are larger than or equal to which of the following values?