3
2
-2
-3
Correct answer is D
The sum of deviations from the mean of a set of numbers equals 0.
\((k+3)^{2} + (k+7) + (-2) + k + (k+2)^{2} = 0\)
\((k^2 + 6k + 9) + (k+7) - 2 + k + (k^2 + 4k + 4) = 0\)
\(2k^{2} + 12k + 18 = 0\)
\(2k^{2} + 6k + 6k + 18 = 2k(k + 3) + 6(k + 3) = 0\)
\(k = -3 (twice)\)