45 | 48 | 15 | 23 | 30 | 35 | 40 | 11 |
29 | 0 | 3 | 12 | 48 | 49 | 18 | 30 |
15 | 30 | 11 | 42 | 23 | 2 | 3 | 44 |
The frequency table for the given distribution is
In the above frequency distribution, the marks 30 are present in class interval 30 – 40 and not in 20 – 30.
Similarly, marks 40 are present in the class interval 40 – 50 and not in 30 – 40.