Page 1 3/3/2017 Chapter 68 The binomial, hypergeometric, and negative binomial random variables Questions answered in this chapter: •What is a binomial random variable? •How do I use the BINOM.DIST and BINOM.DIST.RANGE functions to compute binomial probabilities? •If equal numbers of people prefer Coke to Pepsi and Pepsi to Coke, and I ask 100 people whether they prefer Coke to Pepsi, what is the probability that exactly 60 people prefer Coke to Pepsi and the probability that between 40 and 60 people prefer Coke to Pepsi? about to ship a batch of 10,000 elevator rails to a customer. To determine whether the batch is acceptable, the customer will randomly choose a sample of 100 rails and check whether each sampled rail is defective. If two or fewer sampled rails are defective, the customer will accept the batch. How can I determine the probability that the batch will be accepted? purchasers show up for a flight. If the airline sells 105 tickets for a 100-seat flight, what is the probability that the flight will be overbooked? •The local Village Deli knows that 1,000 customers come for lunch each day. On average, 20 percent order the specialty vegetarian sandwich. These sandwiches are made in advance. How many should the deli make if they want to have a 5 percent chance of running out of vegetarian sandwiches? •What is the hypergeometric random variable? •What is the negative binomial random variable? Answers to this chapter’s questions What is a binomial random variable?