The mean of the data set is 15. What number is missing? 9,12,16,18,23

The number 12 is missing in the data set.

Step-by-step explanation:

The numbers are 9,12,16,18,23. The missing number is assumed to be 'x'

Mean = Sum of the integers / Total number of integers.

15 = (9+12+16+18+23+x) / 6

15 = (78+x) / 6

90 = 78+x

x = 90-78

x = 12