Abstract
In this paper, we investigate the generalized Hyers-Ulam stability of a general cubic functional equation:
f(x + ky) - kf(x + y) + kf(x - y) - f(x - ky) = 2k(k(2) - 1)f(y)
for fixed k is an element of Z(+) with k >= 2 in random normed spaces.