Let X1,X2, . . . ,Xn denote a random sample from b(1, p). We know that ) = p(1 − p)/n. (See Exercise6.4-12.)

(a) Find the Rao–Cramér lower bound for the variance of every unbiased estimator of p.

(b) What is the efficiency of as an estimator of p?

Reference Exercise6.4-12