 Alright, this is a video about calculating binomial probabilities. AirUSA has a policy of booking as many as 25 people on an airplane that can seat only 23. Past studies have revealed that only 85% of the book passengers actually arrive for the flight. In part A, we will find the probability that if AirUSA books 25 people, not enough seats will be available. So we have to calculate the probability we will not have enough seats on that plane. That plane only has 23 seats. They sell as many as 25 tickets. So we have to calculate the probability that 24 people show up and the probability that 25 people show. These are the only two scenarios where there would not be enough seats. So this is actually a binomial experiment because either somebody shows up or they don't. The probability of someone showing up stays fixed and then there are a certain number of trials. As a matter of fact, the number of trials, number of tickets sold would be 25. The probability of its success or the probability somebody shows up is 0.85. So we'll look at the occurrence when there's 24 people that show and then the occurrence when 25 people show. So we'll go to our Google Sheet Spreadsheet and we'll go to the Compute tab. The binomial region, the number of trials will be 25, the probability of a success meaning somebody shows up 0.85 and I'm first looking for 24 people showing up. So lower bound and upper bound will be 24. You get about 0.0759 after you round the four decimal places. Now 25 people showing up, you get about 0.0172, 0.0172 after you round the four decimal places. All right, so let's use these values to calculate the overall probability. So we said the probability 24 people show will be 0.0759 and then the probability 25 people show is 0.0172. This gives the overall probability of 0.0931. This is the probability that there will not be enough seats. This is probability low enough so that overbooking is not a real concern for passengers if you define unusual as 5% or less. So this is 0.05. So let's compare 0.0931 to 0.05. It is greater than 0.05, so it is not unusual. So the answer here would be no, it's not low enough to be a concern. All right, then in part C, 10% or less. So let's compare 0.0931 to 10% or 0.1. It is less than 0.10 or 0.1, 0.0931 is less than 0.1. So in this case, yes, it is low enough to not be a concern. So that's how you work this example. Thanks for watching.