We interested in estimation of the population mean, Let X1, . .., Xo be a random sample from a population with mean and variance . Consider the following estimators for estimating the population mean: 1 = 2X1+ X2 - Xs 2 Compute the expectation and variance of this estimator. O E() = 24 , Var(ji) 14 O E(A) = u , Var(ji) = NI 02 ONon of them O E(A) = 1 , Var(ji) = 02 O E(j) = 2u , Var(ji) 14 = 9 O E(A) - u , Var(ji) = 00 1 -1 02