Question

Draw a histogram table for the following data:

$\begin{array}{ccccc}\text{Class~interval}& 1-10& 11-20& 21-30& 31-40\\ \text{Frequency}& 7& 12& 15& 13\end{array}$

Answer 1

In this example, the class intervals are inclusive. So, first convert the classes into exclusive form.

On making the classes exclusive (i.e. continuous), we get actual class-limits as:

$0.5-10.5,10.5-20.5,20.5-30.5,30.5-40.5$

$\begin{array}{cc}\text{Class~interval}& \text{Frequency}\\ 0.5-10.5& 7\\ 10.5-20.5& 12\\ 20.5-30.5& 15\\ 30.5-40.5& 13\end{array}$