Question

find the mean of the following frequency distribution by step deviation method...?​

Answer 1

Step-by-step explanation:

Class interval width (w) = 8−4=4

Class interval X No. of employees

F d=

i

X−A

Fd

4-8 6 5 -1 -5

8-12 10=A 10 0 0

12-16 14 15 1 15

16-20 18 20 2 40

ΣF=50 ΣFd=50

Mean = A+

Σf

Σfd

×i=10+(

50

50

×4)=10+4=14

D) 14