http://www.ck12.org Chapter 2. Visualizations of Data
It’s All Relative!!
Arelative frequency histogramis just like a regular histogram, but instead of labeling the frequencies on the
vertical axis, we use the percentage of the total data that is present in that bin. This way the numbers reflect the
amountrelativeto the entire data set.
Frequency Polygons
Afrequency polygonis similar to a histogram, but instead of using bins, a polygon is created by plotting the
frequencies and connecting those points with a series of line segments.
To create a frequency polygon for the bottle data, we first find themidpointsof each classification, plot a point at
the frequency for each bin at the midpoint, and then connect the points with line segments. To make a polygon with
the horizontal axis, plot the midpoint for the class one greater than the maximum for the data, and one less than the
minimum.
Here is the frequency polygon constructed directly from the histogram.