Class width and height of intervals

A histogram is a graphical representation of data that creates bins or classes for ranges of data, with the height of each bar representing the frequency of the data in that range.
Class width refers to the range of each interval or group of values on the x-axis of the histogram.
For example, if the data is broken up into groups of 5 (i.e., 0-5, 5-10, 10-15 etc.), the class width is 5.
The class height of a histogram is proportionate to the frequency density, not the frequency. For data grouped into equal class widths, the height will directly depict frequency.

Class width is calculated by taking the difference between the lower and upper limits of each class. In the example above, the class width would be 10 - 5 = 5 for the class 5-10.
Class height or frequency density is calculated by dividing the frequency of each class by the class width. This ensures that classes with wider intervals don’t skew results by appearing to have more data.

A smaller class width allows for a more detailed look at the data distribution, but might also lead to noise in the data due to variability within each group.
A larger class width provides a more general overview, but might conceal interesting details.
Class height reflects the amount of data within each group relative to the width of the group, where larger heights indicate more data per unit on the x-axis.

Practice working with different class widths to see how they impact the overall shape and interpretation of a histogram.
Work on exercises that require calculating the class height or frequency density from raw data.
Understand how to interpret histograms properly, particularly focusing on the influence of class width.
Always remember that the height of a bar in a histogram represents the frequency density, not the frequency.