Question

The following table gives the literacy rate (in percentage) of $35$ cities.

$\begin{array}{cccccc}\text{Class Interval}& 45-55& 55-65& 65-75& 75-85& 85-95\\ \text{No.of cities}& 3& 10& 11& 8& 3\end{array}$

Find the mean literacy rate.

Answer 1

Answer:-

Marks	No. of students $f_i$	$x_i$	$f_i{x}_i$
$45-55$	$3$	$50$	$150$
$55-65$	$10$	$60$	$600$
$65-75$	$11$	$70$	$770$
$75-85$	$8$	$80$	$640$
$85-95$	$3$	$90$	$270$
	$\Sigma f_i=35$		$\Sigma f_i{x}_i=2430$

We know that, arithmetic mean $=\frac{\Sigma f_i{x}_i}{\Sigma f_i}$

$\therefore \text{Mean literacy rate}=\frac{2430}{35}=69.43$