(3) (a) P(XA = 400, XB = 450, Xc = 150) is obtained via dmultinom(x = c(400, 450, 150), p = c(.38, .40, .22)) = 1.014571e-10 (b) P(XB > 500|XA = 200) is given by 1 - pbinom (500, 800, 0.6451) = 0.875 (c) For pairs i, j = A, B, C, the correlations are given by Cor (X., Xi) = Cov(Xi, Xj) -n * Pi * Pi OxOX; n * Pi * (1 - pi) * n * pj * (1 -P;) Cor (XA, XB) =-0.6392, Cor(XA, XC) = -0.4158, Cor(XB, XC) = -0.4336