Further Mathematics Paper 2, WASSCE (SC), 2019

Question 7

 

The table shows the age distribution in years of a group of people.
Age (in years) 1 – 5 6 – 10 11 – 15 16 – 20 21 – 25 26 – 30
Number of people 18 12 25 15 20 10

Using an assumed mean of 13 years, find the mean age of the people.

Observation