The owner of a large company has asked you about the distribution of the ages of the 1000 employees specifically the mean age and the standard deviation of the ages. To answer the owner's questions, you have taken a sample of 100 employees and have constructed the following distribution table

Age

No. of Employees

20 up to 30

17

30 up to 40

20

40 up to 50

25

50 up to 60

20

60 up to 70

18

What is the approximateaverage employee age?

a.45.7

b.42.0

c.45.2

d.42.9