posted by Heidi .
For the following independent random samples, use the z-test and the 0.01 level of significance in testing as an approximation to the unequal variances t-test when comparing two sample means?
H0: µ1 = µ2 versus H1: µ1 ≠ µ2.
x¯1 = 33.5 s1 = 6.4 n1 = 31
x¯2 = 27.6 s2 = 2.7 n2 = 30