Question

The average height of a group of people is $6ft$. $10$ more people are added with an average height of $5ft$, find the average height of the group of people consisting of $60$ people.

Answer 1

$\overline{x}=\frac{n_1\overline{x_1}+n_2\overline{x_2}}{n_1+n_2}$

Given:-

$n_1=50$

$n_2=10$

$\overline{x_1}=6ft.$

$\overline{x_2}=5ft.$

$\therefore \overline{x}=\frac{50\times 6+10\times 5}{50+10}$

$\Rightarrow \overline{x}=\frac{300+50}{60}$

$\Rightarrow \overline{x}=\frac{350}{6}=58.33$