Question #12 A computer store has received two equal-sized truckloads of laptops. In the shipment delivered by Truck A, 5% of the laptops are defective, while 10% of the laptops delivered by Truck B are defective. The two truckloads are mixed. What is the probability that a customer purchases a laptop from Truck A, given that the laptop is defective? Hm t: Use a tree diagram. Question #18 Two coins are selected randomly from a pocket containing one dime and four quarters. The random variable X is the total value in cents of the 2 selected coins. Find EDI). Outcome X Pr(X) X - Pr (X) Question #19 A bag containing 200 unfair coins is dumped onto a table. The probability of HEADS is 0.48 on every coin. Let the random variable X be the number of TAILS that appear. a. Find the expected value of X. b. Find the variance of X. c. Find the standard deviation of X