Question

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

Answer 1

12

Explanation:

The missing number can be calculated by using the formula:

mean = (sum of data)÷(number of data points)

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

90 = 18+16+x+9+12+23

x=90-18-16-9-12-23

x=12

To check, just take the mean while including the found value for x:

mean =
`(18+16+12+9+12+23)/(6)` =
`(90)/(6)` = 15

Answer 2

The answer to the question is 10