The question askes... to show E[Var (Y|X)] <= Var (Y)
I think we should apply the formula for E[Var(Y|X)] first...but I am stuck on it...
Anyone knows wha's the next step? Thanks.
The question askes... to show E[Var (Y|X)] <= Var (Y)
I think we should apply the formula for E[Var(Y|X)] first...but I am stuck on it...
Anyone knows wha's the next step? Thanks.