Two populations are described in each of the cases that follow.

In which cases would it be appropriate to apply the small-sample t-test to investigate the difference between the population means?

a. Population 1: Normal distribution with variance s1 2 Population 2: Skewed to the left with variance s2 2 = s1 2

b. Population 1: Normal distribution with variance s1 2 Population 2: Symmetric distribution with variance s2 2  s1 2

c. Population 1: Skewed to the right with variance s1 2 Population 2: Skewed to the left with variance s2 2 = s1 2

d. Population 1: Normal distribution with variance s1 2 Population 2: Normal distribution with variance s2 2 = s1

e. Population 1: Uniform distribution with variance s1 2 ;
Population 2: Uniform distribution with variance s2 2 = s1 2