Question: The following table gives a distribution of wages:
Weekly wages: 30-35 35-40 40-45 45-50 50-55 55-60 65-65 65-70
No. of workers: 9 108 488 230 112 30 16 7

An individual is taken at random from the above group. Find the probability (i) his wages were under 40, (ii) his wages were 55 or over, and (iii) his wages were either between 45-50 or 35-40.

Solution:

(i) Total wage earners = 9 + 108 +488 + 230 +122 + 30 + 16 + 7 = 1000
No of wage earners earning wages below 40 is = 9 + 108 = 117
Thus (p) = 117/1000 = .117
(ii) No. of wage earners earning wages over 55 is = 30 + 16 + 7 = 53
Hence, (p) 53/1000 = .053
(iii) No. of wage earners earning was between 45-50 or 35-40 is
230 + 108 = 338.
Hence (p) = 338/1000 = .338