15.2 Test for tanning experiment Refer to the previous exercise. For the actual experiment, suppose the participants using the tanning studio got ranks 1 and 2 and the participants using the tanning lotion got ranks 3 and 4.

a. Find and interpret the P-value for the alternative hypothesis that the tanning studio tends to give better tans than the tanning lotion.

b. Find and interpret the P-value for the alternative hypothesis that the treatments have different effects.

c. Explain why it is a waste of time to conduct this experiment if you plan to use a 0.05 significance level to make a decision.