Answer to Question #252308 in Statistics and Probability for pas

Question

Let X and Y be discrete random variables with joint probability distributions given by

f(x,y)=1/4, x=1,2 and y==1,2 zero otherwise.

i)Find the joint moment generating function of X and Y

ii)Using the joint m.g.f obtain in (i) find the covariance between X and Y

iii)Determine whether or not X and Y are independent