2. Let X, Y and Z be independent random variables whose distributions are given by: X~ Bin(25,0.75), Y~ Geo(0.5), Z~ Po(5). a. Plot the probability mass functions outlined above in ONE figure with three subplots, using the same x-axis range for all of the subplots. [3 marks] b. Find a combination of X, Y and Z whose expectation is e2 and whose variance is √√. [10 marks] c. Find a combination of X, Y and Z whose expectation is equal to the variance. [5 marks] d. Compute the covariance of the resulting variable in part (c) with Z. [7 marks]