Answer
The population is all the 500 companies listed in the Standard & Poor's 500. The sample is the 65 companies contacted.
Work Step by Step
The researcher wants to gather information about the staring salaries of companies listed on the Standard & Poor's 500. Therefore, the population would be all the 500 companies on the list. The sample, which is a subset of the population, would be the 65 out of the 500 companies on the list.