A human resources manager at Beta Technologies, Inc., has collected current annual salary figures and related data for 52 of the company’s full-time employees. The data are in the file P4_3.XLS. 

a. Use Excel’s autofilter tool to identify all employees who are male and who have exactly four years of post-secondary education. What is the average salary of these employees?

b. Find the average salary of all female employees who have exactly four years of post-secondary education. How does this mean salary compares to the one obtained in part a?

c. Use Excel’s autofilter tool to identify all employees who have more than four years of post-secondary education. What proportion of these employees are male?