Let Y1, Y2, . . . , Yn denote a random sample from a population having a Poisson distri- bution with mean λ. (a) Find the form of the rejection region for a most powerful test of H0 : λ = λ0 against Ha : λ = λa , where λa > λ0. (b) Recall that Pn i=1 Yi has a Poisson distribution with mean nλ. Indicate how this information can be used to find any constants associated with the rejection region derived in part (a).