Question

The mean of 8 observation is 40 if 5 is added to each observation then what will be the new mean

Answer 1

Mean =total of xifi /n
40=total /8
Total=320
Now new total =320+5=325
New mean =325/80
=4.06
I hope its correct

Answer 2

We know that
Total = Mean x No. of observations
= 40 x 8
= 320

If 5 is added to each of the 8 observations, then the sum of the values will increase by (5×8)=40.

New total = 320 + 40=360

So, New Mean = New Total/No. of observations
= 360/8
= 45