Two populations are described in each of the following cases. 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 a:.

Population 2: Skewed to the right with variance a; = a:.

b. Population 1: Normal distribution with variance a:.

Population 2: Normal distribution with variance a; # u:.

c. Population 1: Skewed to the left with variance a:.

Population 2: Skewed to the left with variance a; = a:.

d. Population 1: Normal distribution with variance a:.
Population 2: Normal distribution with variance u: = u:.

e. Population 1: Uniform distribution with variance cry.
Population 2: Uniform distribution with variance u; = a:.