Question: The CEO of Exploitron, Inc. wants to know the mean and standard deviation for the number of sick days taken by the 20 support personnel working for the company. Unfortunately, however, the data appear only in a grouped format, so the CEO asks you to estimate the mean, and standard deviation. Below are the raw data.

Sick Days Taken Number of Employees

0-2 1

3-5 2

6-8 3

9-11 4

12-14 3

15-17 2

18-20 2

21-23 2

24-26 1