Question

Calculate the mean age using assumed mean method (A=42)
Age 30-34 35- 39 40-44 45-49
Number of men 6 8 18 8 respectively

Answer 1

mean age of the data given is 40.5 by assumed mean method

Answer 2

Answer:

Step-by-step explanation:

CI                     30-34  35-39  40-44  45-49

$f_{i}$                      6             8            18            8  

$x_{i}$                     32          37           42          47

$d_{i}=x_{i}-42$ -10           -5          0          5

$f_{i}d_{i}$                -60            -40            0            40

Let assume the mean $A= 42$

$\therefore\sum{f}_{i}=6+8+18+8=40$

$\sum f_{i}d_{i}=-12-8+0+8=-60$

Mean value  

$M=A+\frac{\sum f_{i}d_{i}}{\sum f_{i}}\\\\\Rightarrow{M}=42+\frac{-60}{40}\\\\\Rightarrow{M}=42-\frac{3}{2}\\\\\Rightarrow{M}=\frac{84-3}{2}\\\\\Rightarrow{M}=\frac{81}{2}=40.5$