To use the Wilcoxon rank sum test as a test for location, you must assume that
A) the obtained data are either ranks or numerical measurements that will be converted to combined ranks.
B) both samples are randomly and independently drawn from their respective populations.
C) both underlying populations from which the samples were drawn are equivalent in shape and dispersion.
D) All the above.

Question

Quizplus · Accepted Answer

All of the above assumptions must be satisfied for the Wilcoxon rank sum test to be a valid test for location. The data must either be ranks or converted to combined ranks, the samples must be randomly and independently drawn from their respective populations, and the underlying populations must be equivalent in shape and dispersion.

To Use the Wilcoxon Rank Sum Test as a Test