The precooked weight of hamburgers at a gourmet hamburger restaurant has been normally distributed with a mean of 5.5 ounces and a standard deviation of 0.15 ounces. A dining-column journalist from the local newspaper enters the restaurant and orders a hamburger. What is the probability that he will receive a hamburger that had a precooked weight less than 5.3 ounces?
If, in a separate visit to the restaurant, the journalist is accompanied by three colleagues who also order a hamburger, what is the probability that at least 2 of these 4 customers will receive a hamburger that had a precooked weight greater than 5.7 ounces?