1) If X and Y have joint probability distribution f(x,y) = 1/4 for x = -3 and y = -5, x = -1 and y = -1, x = 1 an y = 1, and x = 3 and y = 5, find cov(X,Y). i got 8. please confirm.

2) if joint pdf of X and Y is given by

f(x,y) = 1/3(x+y) for 0<x<1, 0<y<2

= 0 elsewhere

find the variance of W = 3X+4Y-5

my answer is coming out weird. can someone show the working please?

“Operator! Give me the number for 911!”