| Marks | 10 – 19 | 20 – 29 | 30 – 39 | 40 – 49 | 50 – 59 | 60 – 69 | 70 – 79 | 80 – 89 | 90 – 99 |
| Frequency | 2 | 2 | 2 | 8 | 13 | 11 | 12 | 10 | 4 |
The table shows the distribution of marks scored by 64 students in a test
(a) Draw a histogram for the distribution.
(b) Use the histogram to estimate the modal score.
Explanation
| Class intervals | F |
Class boundaries |
| 10 - 19 | 2 | 9.5 - 19.5 |
| 20 - 29 | 2 | 19.5 - 29.5 |
| 30 - 39 | 2 | 29.5 - 39.5 |
| 40 - 49 | 8 | 39.5 - 49.5 |
| 50 - 59 | 13 | 49.5 - 59.5 |
| 60 - 69 | 11 | 59.5 - 69.5 |
| 70 - 79 | 12 | 69.5 - 79.5 |
| 80 - 89 | 10 | 79.5 - 89.5 |
| 90 - 99 | 4 | 89.5 - 99.5 |
(b) The model score = 57