Find the critical value(s) for a hypothesis test using asample of size n = 12, a significance level = 0.01 and null hypothesis H₀: 40. Assume that the population SD is unknown.

a. 2.718

b. 2.68

c. 3.11

d. 2.33

Find the critical value for a two-tailed z-test with = 0.07.

1.81

1.96

2.33

2.575