Question

12. The mean of 20 numbers is 18. If 3 is added to each of the first ten
numbers, find the mean of the new set of 20 numbers.
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Answer 1

Answer:

Mean= sum of no.s / no. of items

Mean=20, no. of items=18

Sum of numbers =20×18

=360

20 is added to first ten numbers.

=>20 is added 10 times.

= 20×10=200 is added to 360

360+200=560

New sum of numbers =560

Their mean = 560/20

= 28