Step 1:- Draw two Perpendicular Lines meeting each other at O (i.e., origin), the horizontal line (i.e., x-axis) and the vertical line (i.e., y-axis).
Step 2:- Observations are represented on x-axis. ‘Break’ can be used on x-axis if class intervals are not starting with zero.
Step 3:- Frequency is represented on y-axis by choosing a proper scale. There should be minimum and maximum values of frequency.
Step 4:- Draw rectangular bars of width equal to class size and height equal to frequency of corresponding class intervals.
There should be no gap in between these rectangular bars. It is called Histogram with uniform width. In case where class intervals are continuous but there widths are not same then Histogram with varying class intervals is drawn.
Steps to draw a histogram with varying class intervals:-
Step 1:- Find the minimum class size of the intervals given in the frequency distribution.
Step 2:- Then find length of Rectangle for each class using the formulae-
Length of Rectangle = (Minimum Class Size/ Class Size) x Frequency of the Class
Step 3:- Draw the rectangles with class size as width and length as obtained in step 2.
With the help of these steps we can draw two types of Histograms.