Homework 3 1. According to a study based on the National Survey on Drug Use and Health, marijuana use has increased signicantly among adults age 50 and up. In particular, among people ages 50 to 54} 7.1% have used marijuana in the past year. You walk into a store and see a group of 12 adults born between 1957' and 197'0. Assume that these people can be viewed as a random sample of adults ages 50 to 64. (a) What is the exact probability that exactly three of the people used marijuana in the past year? (b) What is the exact probability that fewer than two of the people used marijuana in the past year? (c) What is the expected number of people who used marijuana in the past year? What is the standard deviation of the number of people who used marijuana in the past year? (d) Say there are 850 people aged 50 to 64 years at an oldies concert. What is the probability that more than 50 of them used marijuana in the past year? An approximate answer is good enough here