Help help.

1. Suppose X, Y has joint probability density function fxx(x,y) = 3(3 - x)(4 - y) if0 5 x X). 1b. Are X and Y independent? Why? 1c. Find the probability density function fx(x) of X. Grade this question? Yes No 2. Suppose X and Y are independent Exponential random variables with E(X) = 1/2 and E(Y) = 1/5. Compute P(Y > X). Compute P(Y 7 | X > 5). Grade this question? Yes No 5. Suppose that X and Y have joint probability mass function PX,Y (1, y) = (2/3)"(3/8)" for positive integers r, y that satisfy 1 0 and y > 0; and fx,y(r, y) = 0 otherwise. Compute P(Y 0, and fy(y) = 0 otherwise. la. For the random variable Y' in question 1, calculate P([Y - 1/4) ;, given that Y = 2. In other words, find P(X > : [ Y =2). Grade this question? Yes No 3 4. Define f(x) = 27/324 for 0