WAEC Further Mathematics 2014 Question 20

Question 20

Statistics

The table shows the distribution of ages of members of a cultural Troupe.
Age (years): 10 − 14, 15 − 19, 20 − 24, 25 − 29, 30 − 34
Frequency: 6, 8, 14, 10, 12
Find the mean of the distribution.

A.23.4
B.23.6
C.24.3
D.24.6

Show the answer and explanation

Answer: A (23.4)

Explanation

Class marks 12, 17, 22, 27, 32: Σfx = 72 + 136 + 308 + 270 + 384 = 1170. Mean = 1170/50 = 23.4.