Question

Assume that a hypothesis test will be conducted with null hypothesis H₀: μ > 20.
Find the critical value for a sample with n = 15 and α = 0.05.

Answer 1

Here n= 15 and α = 0.05 assume that the standard deviation is given to be . The test is given by

This is a left tailed test. Hence we'll be rejecting the hypothesis for lower values of . Thus the critical value for this test is given by

Here I've used the command "qnorm(0.95)" to get the 0.95 percentile of standard normal in R.