Let X ∈{1,2} and Y ∈{3,4} be independent random variables with
PMF-s: fX(1) = 1 2 fX(2) = 1 2 fY (3) = 1 3 fY (4) = 2 3 Answer the
following questions (a) Write down the joint PMF
(b) Calculate P(X + Y 6 5) and P(Y −X > 2)
(c) Calculate E(XY ), E(X2Y ), E(︁X2+1 Y−2)︁
(d) Calculate the Cov(X,Y ), Cov(1−X,3Y + 2) and Var(2X −Y )
(
e*) Calculate Cov(XY,X), Cov(XY,X + Y )...