9514 1404 393
Answer:
x = 135
Explanation:
The sum of the differences from the mean of the known numbers is
-15 +8 -7 +0 -7 = -21
The value of x must have a difference from the mean that is the opposite of this sum. (That is, the total of differences from the mean of all the numbers must be zero.)
x = 114 +21
x = 135