Question

Find the mean of the following frequency distributions:

Weight (kg)	30	31	32	33	34
Number of students	8	10	15	8	9

Answer 1

$Weight\left(kg\right)$ $x_i$	$No.ofstudents$ $f_i$	$f_i{x}_i$
$30$	$8$	$240$
$31$	$10$	$310$
$32$	$15$	$480$
$33$	$8$	$264$
$34$	$9$	$306$
	$\sum f_i=50$	$\sum f_i{x}_i=1600$

$\Rightarrow$ $Mean\left(\overline{x}\right)=\frac{\sum f_i{x}_i}{\sum f_i}$

$=\frac{1600}{50}$

$=32$