3.10.11. Given that y1, . . . ,yn are independent with E(yi) = i and 2 = Var(yi) = E[yi i]2, give intuitive justifications

3.10.11. Given that y1, . . . ,yn are independent with E(yi) = μi and σ 2 = Var(yi) =

E[yi −μi]2, give intuitive justifications for why both ˆ σ 2 ≡ Σni

=1(yi − ˆ yi)2/n and MSE ≡ Σni

=1(yi −

ˆ yi)2/dfE are reasonable estimates of σ 2. Recall that ˆ yi is an estimate of μi.