Managers at Beta Technologies, Inc., have collected current annual salary figures and potentially related data for a random sample of 52 of the company's full-time employees. The data are in the file P2_1.XLS set out below. These data include each selected employee's gender, age, number of years of relevant work experience prior to employment at Beta, the number of years of employment at Beta, and the number of years of post-secondary education.

PROBLEM: Using Excel where possible to generate data and analysis, solve the following:

(a) Estimate a multiple regression model to explain the variation in employee salaries at Beta Technologies using all of the potential explanatory variables.

(b) Using your regression output, determine which of the explanatory variables should be excluded from the regression equation. Provide reasoning for your decision to remove each such variable.