The Wilcoxon Rank Sum test comparing two populations tests the hypothesis H₀: median₁ = median₂ when which of the following conditions holds? A)The standard deviations $\sigma$₁= $\sigma$₂. B)The means $\mu$₁= $\mu$₂. C)Both populations are symmetric. D)The shapes of both populations are the same.

Question

Quizplus · Accepted Answer

The Wilcoxon Rank Sum test does not require the standard deviations or the means of the two populations to be equal. Instead, it assumes that the two populations have the same shape, making option D correct. This non-parametric test is used when the assumption of normality is not met, focusing on medians rather than means, and it requires the distributions to be of the same shape for the comparison to be valid.

The Wilcoxon Rank Sum Test Comparing Two Populations Tests the Hypothesis