Definition of Frequency Polygon
In a Frequency Polygon, a line graph is drawn by joining all the midpoints of the top of the bars of a histogram.
More About Frequency Polygon
- A frequency polygon gives the idea about the shape of the data distribution.
- The two end points of a frequency polygon always lie on the x-axis.
Video Examples: Frequency diagrams/polygons
Example of Frequency Polygon
The frequency polygon shown above represents the number of vehicles that passes through a particular route in different hours. To draw the above diagram first a histogram is drawn and then a line graph is drawn through the midpoints of the top of the bars.
Solved Example on Frequency Polygon
Ques: The number of hours each student of a class spends for studying are 5, 8, 7, 6, 8, 8, 5, 5, 6, 5, 6, and 5 hours. Identify the frequency polygon for the given data.
A. Figure 1
B. Figure 2
C. Figure 3
D. Figure 4
Correct Answer: A
Step 1: The heights of the bars in the histograms indicate the number of hours that the students of a class spend.
Step 2: Observe the heights of the bars in the histograms to match with the given values.
Step 3: Compute the midpoints of the bars and draw the lines along these midpoints.
Step 4: Frequency polygon of this data will be as follows.
Step 5: So, Figure 1 represents the frequency polygon for the given data.