With reference to exercise 4 find the required size of the

Question

With reference to Exercise 4, find the required size of the samples when σ₁ = 9, σ₂ = 13, δ = 80, δ = 86, α = 0.01, and β = 0.01.

Exercise 4

Suppose that independent random samples of size n from two normal populations with the known variances  and  are to be used to test the null hypothesis μ₁ - μ₂ = δ against the alternative hypothesis μ₁ - μ₂ = δ and that the probabilities of type I and type II errors are to have the preassigned values α and β. Show that the required size of the sample is given by