2. Review of Bias and Consistency. As a reminder, an estimator is unbiased if Em) = p, for any sample size, N. An estimator is consistent if PHIL pl) > 0 as N gets big. For our purposes, this is equivalent to the variance going to 0. a) Prove that EU?) = #X- b) Prove that Var(X) = az/N for iid Xi. What happens as N > 00? c) Given a sample {X1, X2, ..., X N}, let fix = X1. Is this unbiased? #18 this consistent