Public Health and Nutrition
The amount of caffeine in a cup of coffee varies considerably, even if it is brewed by the same person, using the same brewing method and ingredients. Suppose the amount of caffeine in an eight-ounce cup of Maxwell House coffee is approximately normally distributed with mean 120 mg and standard deviation 7.75 mg.27
a. What is the probability that a randomly selected cup of Maxwell House coffee will have less than 110 mg of caffeine?
b. What is the probability that a randomly selected cup of Maxwell House coffee will have between 115 and 130 mg of caffeine?
c. A recent article in a medical journal suggests that an eight-ounce cup of coffee with more than 140 mg of caffeine could cause a person's heart to race. What is the probability that a randomly selected cup will have more than 140 mg of caffeine?