Raaj works at the customer service call center of a major credit card bank. Cardholders call for a variety of reasons, but regardless of their reason for calling, if they hold a platinum card, Raaj is instructed to offer them a double-miles promotion. About 10% of all cardholders hold platinum cards, and about 50% of those will take the double-miles promotion. On average, how many calls will Raaj have to take before finding the first cardholder to take the doublemiles promotion?

Raaj works at the customer service call center of a major credit card bank. Cardholders call for a variety of reasons, but regardless of their reason for calling, if they hold a platinum card, Raaj is instructed to offer them a double-miles promotion. About 10% of all cardholders hold platinum cards, and about 50% of those will take the doublemiles promotion. On average, how many calls will Raaj have to take before finding the first cardholder to take the double-miles promotion?

Justine works for an organization committed to raising money for Alzheimer’s research. From past experience, the organization knows that about 20% of all potential donors will agree to give something if contacted by phone. They also know that of all people donating, about 5% will give $100 or more. On average, how many potential donors will she have to contact until she gets her first$100 donor?

Twenty percent of cars that are inspected have faulty pollution control systems. The cost of repairing a pollution control system exceeds $100 about 40% of the time. When a driver takes her car in for inspection, what's the probability that she will end up paying more than$100 to repair the pollution control system?

According to a September 2012 Nielsen study, 58% of teenagers (age 13-18) have a smartphone. If we select 8 teenagers at random, find the probability of each outcome described below. There are exactly 6 smartphones in the group.

A certain tennis player makes a successful first serve 70% of the time. Assume that each serve is independent of the others. If she serves 6 times, what's the probability she gets at least 4 serves in?

A Department of Transportation report about air travel found that, nationwide, 76% of all flights are on time. Suppose you are at the airport and your flight is one of 50 scheduled to take off in the next two hours. Can you consider these departures to be Bernoulli trials? Explain.

A basketball player has made 80% of his foul shots during the season. Assuming the shots are independent, find the probability that in tonight's game he misses for the first time on his fifth attempt.

A student figures that he has a 30% chance of being let out of class late. If he leaves class late, there is a 45% chance that he will miss his train. What is the probability that he misses the train?

A Department of Transportation report about air travel found that airlines misplace about 5 bags per 1000 passengers. Suppose you are traveling with a group of people who have checked 22 pieces of luggage on your flight. Can you consider the fate of these bags to be Bernoulli trials? Explain.

A nervous kicker usually makes 70% of his first field goal attempts. If he makes his first attempt, his success rate rises to 90%. What is the probability that he makes his first two kicks?

Your list of favorite songs contains 10 rock songs, 7 rap songs, and 3 country songs.

What is the probability that a randomly played song is a rap song?

Suppose a computer chip manufacturer rejects 2% of the chips produced because they fail presale testing. What's the probability you find a bad one within the first 10 you examine?

A manufacturer ships toaster s in cartons of 20 In each carton , they estimate a 5% chance that one of the toasters will need to be sent back for minor repairs. What is the probability that in a carton , there will be exactly 3 toasters that need repair?