Question

Consider the following distribution of daily wages of $50$ workers of a factory.

Daily wages (in Rs)	100-120	120-140	140-160	160-180	180-200
Number of workers	12	14	8	6	10

Find the mean daily wages of the workers of the factory by using an appropriate method.

Answer 1

Daily wages	Class-mark $x_i$	No.of workers $f_i$	$f_i{x}_i$
$100-120$	$110$	$12$	$1320$
$120-140$	$130$	$14$	$1820$
$140-160$	$150$	$8$	$1200$
$160-180$	$170$	$6$	$1020$
$180-200$	$190$	$10$	$1900$
		$\sum f_i=50$	$\sum f_i{x}_i=7260$

$Mean=\frac{\sum f_i{x}_i}{\sum f_i}$

$=\frac{7260}{50}$

$=145.2$