Moment The moment-generating function of the random variable X having a chi-squared distribution with v degrees of freedom is Mx(t)=(1-21) show that the mean and variance of the chi-squared distribution with v degrees of freedom are, respectively, v and 2v. H Express the mean of X, u, in terms of a moment about the origin of X P = P1 This moment about the origin can be found by evaluating Mx (0). For any value of t, the derivative identified in the previous step is Use