15.26 Sign test about the GRE workshop In Exercise 15.12 on the effect of a GRE training workshop on the writing, you used the sign test to evaluate the test 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 one-sided sign test for evaluating the effect of the workshop. Interpret.

b. Compare results to those in Exercise 15.12 and indicate what this tells you about the effect that outliers have on this nonparametric statistical method.