An airline estimates that 80% of the people who make a reservation for a certain flight will actually show up for the flight. Suppose the airline sells 22 tickets on this flight and the plane has room for 18 passengers. What is the probability that 19 or more people with tickets will show up for the flight? Round to the nearest hundredth.
A)0.13
B)0.40
C)0.33
D)0.27
E)0.07

Question

Quizplus · Accepted Answer

We can model the number of people who show up as a binomial distribution with parameters n=22 and p=0.8. To find the probability that 19 or more people show up, we can subtract the probability that 18 or fewer people show up from 1. Using a binomial calculator or table, we find that P(X ≤ 18) ≈ 0.674. Therefore, P(X ≥ 19) ≈ 1 - 0.674 = 0.326 or 0.33 rounded to the nearest hundredth. Therefore, the best choice is (C).

An Airline Estimates That 80% of the People Who Make