MATHEMATICS

STATISTICS

ACTIVITIES

Representing data on a frequency polygon
Making sense of grouped data
Mean from grouped data
Histogram of grouped data
Estimating the mode from a histogram
Estimating the mode by calculation method
UNEB questions

STATISTICS

Representing Data on a Frequency Polygon

The information in activity 4 can be represented on a frequency polygon.

  1. Refer to your histogram for the daily maximum temperature; identify the frequency corresponding to 27o C.

  2. Repeat the procedure above for all temperatures.

  3. Join the plotted points with a straight edge.

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  1. What you have joined is called a frequency polygon.

 

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Note:

  1. A frequency polygon should touch the horizontal axis at both ends, crossing at the mid-points of the first and last bars. When this condition is not met, the resulting graph is called a line graph.

  2. The frequency polygon can also be drawn without first drawing a histogram by plotting frequencies against the mid-marks or class marks.

Trial Exercise

In a test marked out of 10, the following results were recorded.

Score

3

4

5

6

7

8

9

10

Frequency

2

3

4

7

8

6

3

1

Draw a frequency polygon to represent the above data.

 

Teachers' guide
Lesson plan
Scheme of work