| Class Interval | 3-6 | 6-9 | 9-12 |
| Frequency | 2 | 6 | 12 |
| 12-15 | 15-18 | 18-21 | 21-24 |
| 24 | 21 | 12 | 3 |
The modal class of the given frequency distribution is 12-15. โด The required mode \[ = l + \left(\cfrac{f_1-f_0}{2f_1-f_0-f_2}\right) \times h \] where \( l = 12, f_1 = 24, f_0 = 12, f_2 = 21, h = 3 \) \[ = 12 + \cfrac{24-12}{2\times24 -12 -21} \times 3 \] \[ = 12 + \cfrac{12}{15} \times 3 \] \[ = 12 + \cfrac{12}{5} \] \[ = 12 + 2.4 \] \[ = 14.4 \, (\text{approx}) \]