Question

Below is given the distribution of money (in Rs.) collected by students for flood, relief fund

Money (in Rs)	$0-10$	$10-20$	$20-30$	$30-40$$	40-50$
No. of Students	$5$	$7$	$5$	$2$	$6$

Find mean of money (in Rs) collected by a student using 'Direct Method'.

Answer 1

Money (in Rs)	Class Mark, $x_i$	No. of Students, $f_i$	$f_i{x}_i$
$0-10$	$5$	$5$	$25$
$10-20$	$15$	$7$	$105$
$20-30$	$25$	$5$	$125$
$30-40$	$35$	$2$	$70$
$40-50$	$45$	$6$	$270$
Total		$\sum f_i=25$	$\sum f_i{x}_i=595$

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

$=\frac{595}{25}$
$=23.8$
Mean of money collected by student is Rs. $23.8$