Working with Discrete Distributions

Let X1 and X2 have the joint pmf fiven by the following

(X1,X2) f(X1,X2)
(1,1) 3/8
(2,1) 1/8
(1,2) 1/8
(2,2) 3/8

Find:
a.the marginal pmfs, f1(x1) and f2(x2)
b. the means, m1 and m2 (mu)
c. the variances, (sigma 1)^2 and (sigma2)^2
d. the covariance, sigma(sub 12)
e. the correlationcoeffiecient, p (rho)
f. are x1 and x2 independent? Why or why not

Let X1 and X2 have the joint pmf given by the following

(X1,X2) f(X1,X2)
(1,1) 3/8
(2,1) 1/8
(1,2) 1/8
(2,2) 3/8

Find:
a.the marginal pmf’s, …

The solution examines discrete distrbutions.