Let X1,...,Xn and Y1,...,Yn be independent samples from N(, 2) and N(, 2) respectively. Determine the

Let X1,...,Xn and Y1,...,Yn be independent samples from N(ξ, σ2) and N(η, τ 2) respectively. Determine the sample size necessary to obtain power ≥ β against the alternatives τ /σ > ∆ when α = .05, β = .9, ∆=1.5, 2, 3, and the hypothesis being tested is H : τ /σ ≤ 1.