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Question
Construct a frequency polygon without using a histogram for the following frequency distribution :
| Class Mark | 10 | 15 | 20 | 25 | 30 | 35 | 40 |
| Frequency | 4 | 20 | 40 | 45 | 30 | 25 | 5 |
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Solution
Steps :
1. On the x-axis , take 1 cm as 5 units and plot class interval.
2. On the y-axis , take 1 cm as 5 units and plot frequency.
3. Mark the given data on the graph. (10,4),(15,20),(20,40),(25,45),(30,30),(35,25),(40,5)
4. Mark two more midpoints of zero frequency on x-axis at the start and at the end.
5. Now connect the points using staright lines.
| Class Mark | Frequency |
| 10 | 4 |
| 15 | 20 |
| 20 | 40 |
| 25 | 45 |
| 30 | 30 |
| 35 | 25 |
| 40 | 5 |
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