Question

the mean of ungrouped data is 12 ,if each observation is doubled then find the mean of new data?

Answer 1

If each observation is changed by x times, then the mean also changes by x times. Here, the each observation is doubled. So the mean will also be doubled.

initial mean = 12
final mean = 12×2 = 24

Answer 2

let the data be a1,a2,a3
(a1+a2+a3)/3=12
a1+a2+a3=36  -------------> 1
given that data is doubled
so, (2a1+2a2+2a3)/3
    =[2(a1+a2+a3)]/3
    =2(36)/3
    =2(12)
    =24
mean of new data is 24