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
