How Do I Create a Polygon Frequency Graph Using Excel?
Microsoft Excel supports the arrangement and calculations needed to create frequency polygon and cumulative frequency polygon charts.
Things You'll Need
- Excel worksheet with frequency and midpoint data
There are two types of polygon frequency graphs that you can create using Microsoft Excel: a frequency polygon and a cumulative frequency polygon. The difference between the two is the former plots the count for each frequency distribution class and a cumulative frequency polygon plots the cumulative frequency of the distribution classes.
Frequency Polygon Chart
A frequency polygon chart plots the frequencies of each class in a frequency distribution. Excel allows you to create a distribution table that supports the creation of the chart.
Enter your data into a frequency distribution on an Excel worksheet that includes columns for the class mid-points and the cumulative frequency of the distribution.
To calculate a class mid-point, use the formula: Lower Limit + ((Upper Limit - Lower Limit) / 2).
Click into the heading at the top of either the Mid-Point column or the Frequency column. While holding down the Control key, highlight the data in the chosen column. While continuing to hold down the Control key, highlight the heading and data in the other column. Release the key and the mouse button. The column headings and the data in each column should now be highlighted.
With the Frequency and Mid-point data selected, click on the Insert tab of the Excel Ribbon and click on the Scatter Chart icon to display its gallery. On this gallery, click on the Scatter with Straight Lines & Markers chart type to create the Frequency Polygon chart.
Cumulative Frequency Polygon Chart
The process to create a Cumulative Frequency Polygon chart is similar to that used to create the Frequency Polygon Chart. The difference is that in place of the frequency of each class, the cumulative frequency of each class is plotted.
Click into the heading of either the Cumulative Frequency column or the Mid-point column and, while holding down the Control key, highlight the data in that column and the heading and data in the other column.
With the Mid-point and Cumulative Frequency data selected, click on the Insert tab of the Excel Ribbon, click on the Scatter chart icon and choose the Scatter with Straight Lines & Markers chart type from its gallery to create the Cumulative Frequency Polygon chart.