Consider the following competing hypotheses and accompanying sample data. The two populations are known to be normally distributed.

H0: µ1 - µ2 ≤ 0

HA: µ1 - µ2 > 0

1 = 20.2
2 = 17.5

s1 = 21.5 s2 = 15.2

n1 = 22 n2 = 18

a. Implement the test at the 5% level under the assumption that the population variances are unknown but equal.

b. Repeat the analysis at the 10% level.