The "20-ounce" package of mozzarella cheese distributed by a food company actually has a weight that is normally distributed, with ounces and ounces.
a. What is the probability that a randomly selected package of this cheese will actually contain at least 20.5 ounces?
b. What is the probability that a randomly selected package of this cheese will actually contain between 20.5 and 21.3 ounces?
c. A shopper randomly selects 8 of these packages. What is the probability that 3 or more of them will contain at least 21.2 ounces of cheese?