The caffeine content of a cup of home-brewed coffee is a normally distributed random variable

with a mean of 115 mg with a standard deviation of 20 mg. (a) What is the probability that a ran�domly chosen cup of home-brewed coffee will have more than 130 mg of caffeine? (b) Less than
100 mg? (c) A very strong cup of tea has a caffeine content of 91 mg. What is the probability that
a cup of coffee will have less caffeine than a very strong cup of tea?