Problem 3: The joint probability density function of random variables X and Y is given by:
fxy(x,y) = k, 0 < y < x < 1
fxy(x,y) = 0, otherwise
a. Find k.
b. Find the best (non-linear) minimum mean squared error (MMSE) estimator for Y given X = 1. [20]
Problem 4:
a. X and Y are zero mean, jointly Gaussian random variables with a correlation coefficient of -0.5 and each with unit variance. Find the variances of:
i) Z = 2X + 3Y
ii) W = X - 2Y
b. X and Y are independent Poisson random variables with a common parameter A. Find the characteristic function of Z = X - Y. [15]