Question

Find the mean:

Class interval:	25-29	30-34	35-39	40-44	45-49	50-54	55-59
Frequency:	14	22	16	6	5	3	4

Answer 1

Let’s consider the assumed mean (A) = 42

From the table it’s seen that,

A = 42 and h = 5

Mean = A + h x (\(\frac{Σf_i u_i}{N}\))

= 42 + 5 x (\(\frac{-79}{70}\))

= 42 – \(\frac{79}{14}\)

= 42 – 5.643

= 36.357