The Effectiveness of Three Brands of Stain Remover (EZ-Clean, SpotX

Multiple Choice

The effectiveness of three brands of stain remover (EZ-Clean, SpotX, and OXYBoost) were rated (A = excellent to F = poor) by different groups of consumers.The appropriate nonparametric procedure to use to determine whether there differences in the perceived effectiveness among the three brands?

A) Wilcoxon Signed-Rank test.
B) Wilcoxon Rank Sum test.
C) Kruskal Wallis test.
D) Spearman's rho.
E) Mann-Whitney test.