Tom Fadden lists the number of sales calls he made on each of the past 14 days: 

Sales Calls x                                       No. of days f(x)

4……………………………………..             1

5……………………………………..             3

6……………………………………..             4

7……………………………………..             4

8……………………………………..             2

                                          Total = 14

a. Compute the mean number of sales calls made per day over the 14-day period. (Treat the data as a sample.)

b. What is the median number of calls?

c. Compute the variance and the standard deviation for his daily call rate during the 14-day period.