Question

Consider the following distribution of daily wages of 150 workers of a factory. Find the
mean daily wages by step deviation method.
Daily Wages (in Rs ) 20−30 30 −40 40 −50 50 −60 60 −70
Number of workers 25 40 42 33 10

Answer 1

Dear student,
​​​​​​A = 45 and h = 10

Daily wages (in Rs)	xi	fi	ui = (xi - A)/h	fiui
20-30	25	25	-2	-50
30-40	35	40	-1	-40
40-50	45	42	0	0
50-60	55	33	1	33
60-70	65	10	2	20
		∑fi = 150		∑fi ui = -37

Mean = A + h x ($\frac{\sum f_i{u}_i}{\sum f_i}$)
= 45 + 10 x (-37/150)
= 45 - (37/15)
= 45 - 2.47
= 42.53
Mean daily wages = Rs 42.53

Regards