Which of these tests is a nonparametric method to compare two populations when the samples are matched pairs and the data are interval, and where the normality requirement necessary to perform the parametric test is unsatisfied?
A) the Wilcoxon rank sum test
B) the sign test
C) the matched pairs t test
D) the Wilcoxon signed-rank test

Question

Quizplus · Accepted Answer

The Wilcoxon signed-rank test is a nonparametric method used to compare two populations when the samples are matched pairs and the data are interval, and where the normality requirement necessary to perform the parametric test is unsatisfied. The Wilcoxon rank sum test and the sign test are nonparametric tests, but they are used when the samples are independent rather than matched pairs. The matched pairs t test is a parametric test that is used when the normality assumption is satisfied. Therefore, the best choice in this scenario is the Wilcoxon signed-rank test.

Which of These Tests Is a Nonparametric Method to Compare