Refer to Exercise 33, and consider a confidence interval associated with the sign test: the sign interval. The relevant hypotheses are now 
a. Suppose we decide to reject H0 if either Y ≥ 15 or Y ≤ 5. What is the smallest a for which this equivalent to rejecting H0 if P-value ≤ a?
b. The confidence interval will consist of all values µ ,0 for which H0 is not rejected. Determine the CI for the given data, and state the confidence level.