Every year MBA programs across the country advertise for prospective students. They promote the academic excellent of their programs, the uniqueness of their offerings, the quality of their faculty and a variety of other factors. In a competitive market, the goal is to attract the brightest and the best. Many schools claim that graduates of their programs will see large salaries on graduation. This is clearly a very important part of many students' decision criteria. In fact, the Financial Times rating of MBA programs uses graduates' salaries as a large component of their rating system. Now you access to the salary data from a prominent MBA school in North America. Please analyze the data and see what factors are associated with higher salaries.

Q$1$: What is the independent and dependent variable?

Q$2$: How to determine sample size?

Please explain I$\text{'}$m completely lost.