## expectation of the sum of squares

Hi, i'm having trouble doing the following question. (It's about two-way analysis of variance). I'd appreciate any help.

Thanks.

Define the sum of squares for factor A as
SSA = bn(sum i=1,...,a)(Y i•• − Y •••)^2

By expanding the brackets and considering the expectations of Y^2i•• and Y^2•••, show that

E(SSA) = (a − 1)sigma^2+ bn(sum i=1,...,a)alpha^2