a buyer for a specialty clothing manufacturer must buy at least 2000 bales of cotton that weigh at least 420 kilograms per bale. a cotton broker has a shipment of 100,000 bales with weights that are normally distributed with a mean of 376 kilograms and a standard deviation of 22 kilograms. how many bales should the buyer purchase to ensure that he has at least 2000 bales that weigh 420 kilograms each?