If you set the following hypothesis for differences between population averages, these are:
H0: mu;1 = mu;2
H0: mu;1 not equal to; mu;2
a. You must apply a test of a tail to the left
b. None of the above
c. You must apply a test of a tail to the right
d. You must apply a two-tailed test
This solution correctly identifies which tailed test must be applied to the hypothesis.