Question

Draw a histogram to represent the following data:
$\begin{array}{cccccc}\text{Class interval}& 10-14& 14-20& 20-32& 32-52& 52-80\\ \text{frequency}& 5& 6& 9& 25& 21\end{array}$

Answer 1

Sol:

Class interval	10-14	14-20	20-32	32-52	52-80
Frequency	5	6	9	25	21

In the above table, class intervals are of unequal size, so we calculate the adjusted frequency by using the following formula:

Adjusted Frequency = Minimumclasssize×itsfrequencyClasssizeofthisclass

Thus, the adjusted frequency table is:

Class Intervals	Frequency	Adjusted Frequency
10-14	5	45×5=5
14-20	6	46×6=4
20-32	9	412×9=3
32-52	25	420×25=5
52-80	21	428×21=3

Now, take class intervals along x-axis and adjusted frequency along y-axis and constant rectangles having their bases as class-size and height as the corresponding adjusted frequencies.

Thus, we obtain the histogram as shown below: