9514 1404 393
Answer:
A. It is 8 below the mean
Explanation:
The sum of differences from the mean is always zero. If x is the difference from the mean that the fourth data value has, then we must have ...
3 + 4 + 1 + x = 0
x = -8 . . . . . . . . . subtract 8
The fourth data value must be 8 below the mean.
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Additional comment
I find this property of the mean to be very useful in solving any number of problems related to differences from an actual or a desired mean.