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,is the:
A)Wilcoxon rank sum test.
B)sign test.
C)matched pairs t-test.
D)Wilcoxon signed rank sum test.

Question

Quizplus · Accepted Answer

The Wilcoxon signed rank sum test is the appropriate nonparametric method to compare two populations when the samples are matched pairs and the data are on an interval scale, but the normality assumption for a parametric test is not met. This test works by ranking the differences between the pairs and testing whether the median of these differences is zero. The other options (A, B, and C) are each for different scenarios where the matching and/or data type differs.

A Nonparametric Method to Compare Two Populations,when the Samples Are