The owner of a local nightclub has recently surveyed a random sample of n = 50 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Her null and alternative hypotheses are:

H ₀ : μ ≤ 30

H _a : μ > 30.

If she wants to have a level of significance at 0.01, what rejection region should she use?

a. Reject if tc> 1.677

b. Reject if tc> 2.405

c. Reject if tc< 2.405

d. Reject if tc> 2.326