Question

A Statistics assignment is created by choosing for each question on the assignment one possible version at random from a bank of possible versions of the question. There are 20 versions in the bank for each question.
A specific question on the assignment involves a one-sample test for the population mean with hypotheses
H0 : µ = 15 Ha : µ < 15
with all versions of the question involving a sample of size n = 35.
Seven versions of the question give the population standard deviation as σ = 3. Six versions give the sample standard deviation as s = 4.2. The remaining versions give the sample standard deviation as s = 5.7.
Let c∗ be the critical value for the rejection region on this question. Calculate E[c∗].

Answer 1