Question

The ages of $5$ girls in a group are : $16$ years $4$ months; $15$ years $8$ months ; $14$ years $9$ months; $15$ years $3$ months and $14$ years $8$ months. Find their mean.

Answer 1

Given that the ages of $5$ girls in a group are
$16years4months$
$15years8months$
$14years9months$
$15years3months$
$\underset{–}{14years8months}$
$\underset{–}{74years32months}$ is the sum of ages of $5$ girls.
Since, $12$ months $=1$ year
$\Rightarrow 1$ month $=\frac{1}{12}$ year
$\Rightarrow 32$ months $=\frac{32}{12}$ years
$\Rightarrow 32$ months $=2\frac{8}{12}$ years
$\therefore 32$ months $=2.7$ years
Thus, the sum of ages of five girls $=74+2.7=76.7$ years.
Since, mean $\overline{x}=\frac{\text{sum of observation}}{\text{total number of observation}}$
$\overline{x}=\frac{76.7}{5}$
$\therefore$ mean $\overline{x}=15.34$ years.