Question

Find the mean of the given data.

$\begin{array}{cc}Classinterval& Frequency\\ 0-100& 7\\ 100-200& 11\\ 200-300& 15\\ 300-400& 9\\ 400-500& 8\end{array}$

Answer 1

$\begin{array}{ccc}\text{Class Mark}& \text{Frequency}& f_i{x}_i\\ \text{50}& \text{7}& \text{350}\\ \text{150}& \text{11}& \text{1650}\\ \text{250}& \text{15}& \text{3750}\\ \text{350}& \text{9}& \text{3150}\\ \text{450}& \text{8}& \text{3600}\end{array}$

$\sum f_i=50$

$\sum f_i{x}_i=12500$

Mean
$=\frac{12500}{50}$

$=250$