Exercise 11.4 The usual model for a randomized complete block design was given in Section 8.2 as yi j = μ + αi + βj + ei j , i = 1, . . . ,

a, j = 1, . . . ,

b, Var(ei j ) = σ2, and Cov(ei j , ei  j  ) = 0 for (i, j ) =

(i 

, j 

). The βj s are considered as fixed block effects. Consider now a model yi j = μ + αi + βj + ηj + ei j .