This exercise shows that the sample variance is an unbiased estimator of the population variance when Y..... Y are i.i.d. with mean y and variance a

a. Use Equation (2.31) to show that E[(Y - Y] = var(Y) - 2cov(YY)+var(Y).

b. Use Equation (2.33) to show that cov(Y.Y) = on.

c. Use the results in parts

(a) and

(b) to show that E(s) =