A nonparametric method to compare two populations, when the samples are independent and where the normality requirement necessary to perform the parametric test is not satisfied, is the:
A) Wilcoxon rank sum test
B) sign test
C) Wilcoxon signed rank sum test
D) equal-variance t-test of
E) chi-square text

Question

Quizplus · Accepted Answer

The Wilcoxon rank sum test is a nonparametric test that compares two independent populations when the normality assumption is not satisfied. It is based on the ranks of the observations and does not require knowledge of the underlying distribution. Therefore, it is a more appropriate choice than the other options. The sign test is another nonparametric test, but it is used for comparing two related populations. The Wilcoxon signed rank test is used for the same purpose, but for related populations. The equal-variance t-test assumes normality and equal variances, which is not the case here, while the chi-square test is used for categorical data.

A Nonparametric Method to Compare Two Populations, When the Samples