Let X1,..., Xn be a random sample from a negative binomial distribution with pmf x + r - 1 x 1 - p)x, 0 ≤ p ≤ 1,x = 0, 1, 2,....
p(x, r, p) = p ( r - 1
Find method of moments estimators for r and p. [Here E[X] = r(1 - p)/p and E X2 = r(1 - p)(r - rp + 1)/p2.]