JAMB 2013 · UTME · Q44

Age	20	25	30	35	40	45
No. of people	3	5	1	1	2	5

Calculate the median age of the frequency distribution.

Worked solution (try it first)

There are $3 + 5 + 1 + 1 + 2 + 5 = 17$ people, so the median is the $\frac{17 + 1}{2} = 9$ th age.
Running totals: 3 (age 20), 8 (age 25), 9 (age 30).
The 9th person is 30, so the median age is 30, option D.