JAMB 1984 · UME · Q37

The cumulative frequency function of the data below is $y = cf(x)$ . What is $cf(5)$ ?

Score	3	4	5	6	7
Frequency	30	32	30	35	20

Worked solution (try it first)

$cf(5)$ is the number of scores that are 5 or less, so add the frequencies for scores 3, 4 and 5.
$30 + 32 + 30 = 92$ , so $cf(5) = 92$ , option E.