An alalysis of monthly wages paid to the workers in two firms A and B belonging to the same industry the following result:

The average of monthly wages and variance of distribution of wages of all workers in the firms A and B taken together are

Options

A. Rs 1860, 100
B. Rs 1750, 100
C. Rs 1800m, 81
D. None of the above

Answer

D

Explanation

Combined Average
`=(500xx1860+600xx1750)/(1100)=1800`
Combined Variance
`=(500(81+3600)+600(100+2500))/(1100)`
`=((5xx3681)+(6xx2600))/(1100)~~3092`