2. $X_1, X_2, X_3$ are selected from population that corresponds to ($\mu, \sigma^2$) and they are not independent. That is, $Cov(X_1, X_2) = Cov(X_1, X_3) = Cov(X_2, X_3) = 0.5\sigma^2$. When $Y = (X_1 + 2X_2 + X_3)/3$, find the following: $E(Y)$, $Var(Y)$, $Cov(X_1, Y)$.