Question

Find the mean:

Class interval:	0-8	8-16	16-24	24-32	32-40
Frequency:	5	6	4	3	2

Answer 1

Let’s consider the assumed mean (A) = 20

From the table it’s seen that,

A = 20 and h = 8

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

= 20 + 6 x (\(\frac{-9}{20}\))

= 20 – \(\frac{72}{20}\)

= 20 – 3.6

= 16.4