Question

Find mean of first 9 multiple of 3

Answer 1

Answer:

12

Step-by-step explanation:

the first nine multiples of three are:3,6,9,12,15,18,21,24,27

so the mean of all these terms is:

    (3+6+9+12+15+18+21+24+27)/9

now for easier calculations we can observe that the numerator is in Arithmetic progression with first term as 3 and common difference 3

sum of n term in an arithmetic progression is:

             n(2a+(n-1)d)/2   so here number of terms(n)=9;a=3;d=3

      9(6+18)/2=12*9=108 is our numerator

so the mean is simply 108/9 which is equal to 12

so the mean we require is 12

I REALLY HOPE THIS HELPS YOU