(Q10). Consider the following distribution of daily wages of 50 workers of a factory.

Daily wages in Rupees	200-250	250-300	300-350	350-400	400-450
Number of workers	12	14	8	6	10

Find the mean daily wages of the workers of the factory by using an appropriate method.

Solution:

Daily wages in Rupees(Class Interval)	Number of workers(fi)	Class marks(xi)	di = xi - 275 [(xi - a)]	fidi
200-250	12	225	-50	-
250-300	14	275 a	0
300-350	8	325	50
350-400	6	375	100
400-450	10	425	150
-	∑fi = 50	-	-	∑fidi =

Here the x_i are of large numerical values.

So we use deviation method then,

Here the assumed mean is taken as 275.