3 . Suppose that a grocery store purchases 4 cartons of skim milk at the wholesale price of $1.00 per carton and retails the milk at $1.50 per carton. After the expiration date, the unsold milk is removed from the shelf and the grocer receives a credit from the distributor equal to three-fourths of the wholesale price. The grocer is not penalized for any product shortage. Given the probability distribution of the random variable X, the number of cartons that are sold from this lot is as follows: \"-s X 0 1 2 3 4 5 ifgx) 1(15 zaps 2l15 3115 ms 3(151 a. Construct the cumulative distribution function of f(x) 1). How many cartons are expected to be sold? c. What is the expected profit of the grocer? d. Calculate for the standard deviation of the grocer's prots