a) [5 points) Let 2'11: .212? - - - , A.\" be an iid random sample irom a normal distribution with parameter p. = 0 and variance 0'2. Show that X? i=5. i=1 n is an unbiased estimator of 02. (b) (8 points) If 6% and 5T1 are unbiased estimator of 9, what condition most be imposed on the constants in and is; so that . A mm | 1:262 is an unbiased estimator of H. (e) (8 points) Let X1, X2, . - - TX be an iid random sample from a poisson distribution with parameter A. IOne possible estimator for A is A given by 12%201'1X Show that i is an unbiased estimator of A