Question

There are 50 numbers each number is subrated from 53 and the mean of the numbers so obtained is found to be -3.5 find the mean of given number

Answer 1

let the no . be 1x ,2x ,3x, 4x,.....................................,49x,50x.

given each no. is subtracted from 53 the  new no. are 53-1x ,53-2x,53-3x ,.................................. ,53-49x ,53-50x

the mean of these no.  is -3.5

( 53-1x+53-2x+53-3x +..............................+53-49x +53-50x)/50 = -3.5

2650-(1x+2x+3x+................................+49x+50x)=-175

1x+2x+3x+................................+49x+50x =2825

mean of the original no. =2825/50 = 56.5