Question

Find the mode of the following data:

Class:	Frequency:
0 – 20	6
20 – 40	8
40 – 60	10
60 – 80	12
80 – 100	6
100 – 120	5
120 – 140	3

Answer 1

Modal class = 60 – 80

∴ Mode = `l + (f_1 - f_0)/(2f_1 - f_0 - f_2) xx h`

Hence, l = 60, f₁ = 12, f₀ = 10, f₂ = 6 and h = 20

Mode = `60 + (12 - 10)/(2 xx 12 - 10 - 6) xx 20`

= `60 + (2 xx 20)/(24 - 16)`

= `60 + 40/8`

= 60 + 5

= 65