NECO 2022 · Paper 1 · Q56

Find the mode of the distribution below, correct to one decimal place.

Class	20 – 24	25 – 29	30 – 34
Frequency	3	7	2

Worked solution (try it first)

The modal class is 25 – 29 (frequency 7).
Its lower class boundary is $L = 24.5$ and the class width is $c = 5$ .
The differences are $\Delta_1 = 7 - 3 = 4$ and $\Delta_2 = 7 - 2 = 5$ .
Mode $= L + \dfrac{\Delta_1}{\Delta_1 + \Delta_2} \times c$
$= 24.5 + \frac{4}{9} \times 5$
$\approx 26.7$ , option E.