Question

The mean of 30 numbers is 18, What will be the new mean if each number is multiplied by 4?

Answer 1

Answer:

Given that the mean of 15 numbers is 27

i.e n=15

mean =27

we know

Mean =

No. of numbers(observations)

sum of numbers

27=

15

sum of numbers

Sum of numbers =15×27=405

and if each number multiplied by 4.

After multiplication of each number their new sum of numbers will be

=405×4

=1620

∴ new mean =

no. of numbers(observations)

new sum of numbers

=

15

1620

=108

∴ new mean =108