Question

The mean of three number is 15. if 2 of the numbers are 18 and 16 what is the third number​

Answer 1

11

Explanation:

The mean is calculated as

mean =
`(sum)/(count)`

let the third number be x , then

`(18+16+x)/(3)` = 15 ( multiply both sides by 3 to clear the fraction )

34 + x = 45 ( subtract 34 from both sides )

x = 11 ← third number