Suppose that X1, . . . , Xn are independent and identically distributed Poisson(?) random variables with probability function

Suppose that X1, ...; Xn are independent and identically distributed Poisson(A) ran- dom variables with probability function f (I; A) = r = 0, 1, 2, ... Define X and S as X =. _EX; and 5= 15X?. i=1 i=1 (c) Show that E(S) = A(A + 1). (d) Let D = 5 - X. Show that D is an unbiased estimator of 13