7.1

(a) Consider a population {a1,...,aN } with the parameter space defined by the restriction a1 + ··· + aN = A (known). A simple random sample of size n is drawn in order to estimate τ 2. Assuming the labels to have been discarded, show that Y(1),...,Y(n) are not complete.

(b) Show that Theorem 7.1 need not remain valid when the parameter space is of the form V1 × V2 ×···× VN . [Hint: Let N = 2, n = 1, V1 = {1, 2}, V2 = {3, 4}.]