Frequency Polygon

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.

     example of  Frequency Polygon
    Choices:
    A. Figure 1
    B. Figure 2
    C. Figure 3
    D. Figure 4
    Correct Answer: A

Solution:

    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.
       example of  Frequency Polygon
    Step 5: So, Figure 1 represents the frequency polygon for the given data.

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