Exam 15: A:nonparametric Statistics

Which of these tests employs matched pairs sampling?

A two-sample t test with independent samples corresponds to a Wilcoxon signed-rank test for paired samples.

Which of the following will NEVER be a required condition of a nonparametric test?

Consider the following data set: 14, 14, 15, 16, 18, 19, 19, 20, 21, 22, 23, 25, 25, 25, 25, and 28. What is the rank assigned to the four observations of value 25?

Nonparametric statistical methods generally specify hypotheses in terms of population distributions rather than parameters such as means and standard deviations.

A one-sample t test is the parametric counterpart of the Friedman test for randomized block experimental design.

In a Kruskal-Wallis test for comparing three populations, the test statistic is calculated as H = 2.80. If the test is conducted at the 5% significance level, then what may one conclude?

The Spearman's rank correlation coefficient must lie between which of the following values?

We can use the Friedman test to determine whether a difference exists between two populations. However, if we want to determine whether one population location is larger than another, we must use the sign test.

The Wilcoxon signed-rank test is a nonparametric test that (1) uses the directions of differences observed in a matched pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another, and (2) determines whether a sample comes from a population with a specified median.

Nonparametric tests are often more efficient than parametric tests.

In a Wilcoxon signed-rank test for matched pairs with n = 35, the rank sums of the positive and negative differences are 380 and 225, respectively. What, then, is the value of the standardized test statistic z?

A Wilcoxon rank sum test for comparing two independent samples involves two samples of sizes 6 and 9. The alternative hypothesis is that the location of population 1 is to the left of the location of population 2. Using a 0.05 significance level, the appropriate critical values are 31 and 65.

Which of the following distributions approximates the Kruskal-Wallis test statistic H when the objective is to compare k distributions and the sample sizes are greater than or equal to 5?

The Wilcoxon signed-rank test is a nonparametric test that uses the directions of differences observed in a matched pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another.

The critical value is taken from the F distribution whenever the Wilcoxon signed-rank test is employed.

The significance level for a Wilcoxon signed-rank test is 0.05. The alternative hypothesis is stated as: The location of population 1 is to the left of the location of population 2. Under these circumstances, what is the appropriate critical value for a sample of size 20 (i.e., the number of non-zero differences)?

When assigning ranks during a Wilcoxon rank sum test, tied values are each given the mean of the next ranks to be assigned. Which of the following statements is NOT correct regarding this averaging procedure?

In a Friedman test for comparing four populations, provided that there are eight blocks, the test statistic is calculated as = 10.98. If the test is conducted at the 5% significance level, what may we conclude about the null hypothesis and the p-value?

In a Wilcoxon signed-rank test for matched pairs with n = 32, the rank sums of the positive and negative differences are 367.5 and 160.5, respectively. Given this information, what is the value of the standardized test statistic z?