7. Suppose that Yij follows the single factor ANOVA model: Yij = Hi + Gij, i= 1, . .. , 1, j = 1, . .. , ni, where Gj are i.i.d. Normal(0, o2) random variables. Let Yi. = _ _" Yij denote the sample mean of responses in the ith treatment group. Let Y. = El=1 EY Yij denote the overall sample mean of all observed responses, where nT = =n; is the total sample size. Show that: a. Y. = LEInYi b. E( Y.. ) = m Ei, niki c. Var( Y.) =