Question

Find the mean of the following frequency distribution:

Variable (xi)	10	30	50	70	89
Frequency (fi)	7	8	10	15	10

Answer 1

We will make the following table:

Variable (xi)	Frequency (fi)	(fi)(xi)
10	7	70
30	8	240
50	10	500
70	15	1050
89	10	890
	$\sum _{}^{}{f}_i=$50	$\sum _{}^{}{f}_i{x}_i=$2750

Thus, we have:

$\mathrm{Mean}=\frac{{\displaystyle \underset{}{\overset{}{\sum f_i{x}_i}}}}{{\displaystyle \sum _{}^{}}{x}_i}$
$=\frac{2750}{50}=55$