A Histogram of equal class intervals has an equal width of all rectangles indicating the same class intervals. In contrast, a Histogram of unequal class intervals has rectangles of varying width as per their corresponding class intervals. Before constructing a Histogram, frequencies of unequal class intervals are to be adjusted. The adjustment factor of each class is calculated with the following formula.
Adjustment factor for any class = \(\frac{\text{Class Interval of the Concerned Class}}{\text{Lowest Class Interval}}\)
And the adjusted frequency will be calculated by dividing the original frequency by adjustment factor.
