11. (6 points) Suppose that the amount of milk produced by dairy cows per day at a certain dairy is normally distributed with a mean of 5.9 gallons and a standard deviation of 0.6 gallons. a) If one dairy cow is randomly selected, find the probability that this cow produces more than 6.0 gallons of milk per day. Round to four decimal places. b) If a sample of size n = 50 is drawn randomly from the dairy, find the probability that the sample mean milk production is more than 6.0 gallons per day. Round to four decimal places.