Question

If the
average (arithmetic
mean) of 2, 7, and x is 12,
what is the value of x?

Answer 1

x = 27

Explanation:

mean is calculated as

mean =
`(sum)/(count)`

sum = 2 + 7 + x = 9 + x and count = 3 , then

`(9+x)/(3)` = 12 ( multiply both sides by 3 to clear the fraction )

9 + x = 36 ( subtract 9 from both sides )

x = 27