Question

A researcher randomly sampled 30 graduates of an MBA program and recorded data about their starting salaries. Of primary interest to the researcher is whether starting salaries differ based on gender. The researcher performs apooled-variance t-test of the mean salaries of the females (Population 1) and males (Population 2) in the sample. Assume α = 0.10.

1. What assumptions are necessary to conduct this hypothesis  test?

a		The population variances are approximately equal.
b		All of the above assumptions are necessary.
c		Both populations of salaries (male and female) must have approximate normal distributions.
d		The samples were randomly and independently selected.

Answer 1

The researcher performs a pooled variance t-test of mean salaries of the females and males in the sample. We know that, to perform a pooled variance t-test, the necessary assumptions are:

• Both populations of salaries(male and female) must have approximate normal distributions.
• The samples were randomly and independently selected.
• The population variances are approximately equal.

Therefore, the correct answer is:

b. All of the above assumptions are necessary.