21. Call centers have high turnover rates because of the stressful environment. The national average is approximately 50%. The director of human resources for a large bank has compiled data about 70 former employees at one of the bank’s call centers (see the Excel file Call Center Data). Use PivotTables to find these statistics:

a. the average length of service for males and females in the sample

b. the average length of service for individuals with and without a college degree

c. the average length of service for males and females with and without prior call center experience