| Class Interval | $10–19$ | $20–29$ | $30–39$ | $40–49$ | $50–59$ |
| Frequency | $28$ | $23$ | $15$ | $20$ | $14$ |
(iv)
| Marks obtained | Less than 10 | Less than 20 | Less than 30 | Less than 40 | Less than 50 |
| Number of Students | $8$ | $22$ | $48$ | $60$ | $75$ |
(iii)
Steps to draw a histogram for given frequency distributions,
1. On the x – axis $1cm=10$ units and take the frequency.
2. On the y – axis, take $1cm=10$ units and plot class interval.
Then,
| Less than | Cumulative Frequency |
| $19$ | $28$ |
| $29$ | $51$ |
| $39$ | $66$ |
| $49$ | $86$ |
| $59$ | $100$ |
3. So, in the graph mark the points with coordinates having abscissae as actual limits and ordinates as the cumulative frequencies, $(19,28)$, $(29,51)$, $(39,66)$, $(49,86)$, $(59,100)$.
4. Finally join the points plotted by a smooth curve.
(iv)
Steps to draw a histograms for given frequency distributions,
1. On the x – axis $1cm=10$ units and take the frequency.
2. On the y – axis, take $1cm=10$ units and plot plot class interval.
Then,
| Marks less than | Cumulative Frequency |
| $10$ | $8$ |
| $20$ | $22$ |
| $30$ | $48$ |
| $40$ | $60$ |
| $50$ | $75$ |
3. So, in the graph mark the points with coordinates having abscissae as actual limits and ordinates as the cumulative frequencies, $(10,8)$, $(20,22)$, $(30,48)$, $(40,60)$, $(50,75)$.
4. Finally join the points plotted by a smooth curve.