If X and Y are independent random variables with the µx = 5, µy = 2 and sx^2 = 1, sy^2 = 2.
a) Determine the Mean (Expected value) of the random variable Z = 3X - 2Y + 5
b) If x and y are the sample means of the random variables X and Y, show that 3x - 2y + 5 is an unbiased estimator for mean of Z.