15.27 Wilcoxon signed-rank test about the GRE workshop Example 8 on the GRE workshop used the Wilcoxon signed-rank test to evaluate the score differences of 0.5,

-0.5, and 1.5. Suppose the test differences were 5.5, -0.5, and 1.5 instead of 0.5 -0.5, and 1.5.

a. State the hypotheses and find the P-value for the onesided Wilcoxon signed-ranks test for evaluating the effect of the workshop. Interpret.

b. Compare results to those in Example 8 and indicate what this tells you about the effect that outliers have on this nonparametric statistical method.