Question

Calculate arithmetic mean using direct method for the following data shows distance covered by $50$ persons to perform their work inside the factory.

• A. $20.5km$
• B. $32.8km$
• C. $25.2km$
• D. $27.6km$

Answer 1

The correct option is B $32.8km$

Answer:- Using direct method

Representing the data into frequency distribution table

$x_i=\text{mid point of each class interval}$

Class interval	No. of workers $\left(f_i\right)$	$x_i$	$f_i{x}_i$
1-11	4	6	24
11-21	6	16	96
21-31	10	26	260
31-41	12	36	432
41-51	18	46	828
	$\Sigma f_i=50$		$\Sigma f_i{x}_i=1640$

$\therefore mean=\frac{\Sigma f_i{x}_i}{\Sigma f_i}=\frac{1640}{50}=32.8$

Average distance covered by 50 persons = 32.8

B)32.8