Question

A data set consists of 9 numbers. The mean of the data set is 15. One of the numbers in the data set is then deleted. The mean of the data set is now 16. What number in the days set was deleted?

Answer 1

Explanation:

mean=15

number of terms=9

total of 9 numbers=15×9=135

number of terms=8

mean=16

total=16×8=128

number deleted=135-128=7