Question

The mean of 20 numbers is 43. If 6 is subtracted from each of the numbers, what will be the new mean?

Answer 1

Mean =(x1+x2------x20)/20

43={x1+x2-----x20}/20

43*20=860={x1+x2----x20)


If 6 is subtracted from 20 observations, it means that (20*6)is subtract from whole all observations

Mean ={(x1+x2-----x20)-120}/20

Mean =(860-120)/20

New mean =740/20

New mean =37