Question

Draw a frequency polygon from the information given in the following table.

| Age of blood donar (Years) | No. of blood donars |
| Less than 20 | 0 |
| Less than 25 | 30 |
| Less than 30 | 75 |
| Less than 35 | 127 |
| Less than 40 | 165 |
| Less than 45 | 185 |
| Less than 50 | 197 |

Answer 1

| Class (Age of blood donor) | Class mark | Frequency (No. of donors) | co-ordinates |
| 15-20 | 17.5 | 0 | (17.5, 0) |
| 20-25 | 22.5 | 30 | (22.5, 30) |
| 25-30 | 27.5 | 45 | (27.5, 45) |
| 30-35 | 32.5 | 52 | (32.5, 52) |
| 35-40 | 37.5 | 35 | (37.5, 38) |
| 40-45 | 42.5 | 20 | (42.5, 20) |
| 45-50 | 47.5 | 12 | (47.5, 12) |
| 50-55 | 52.5 | 0 | (52.5, 0) |

Draw the axes. Plot points choosing a proper scale. Draw the frequency polygon.