Question

Past records indicate that 15 percent of the flights for a certain airline are delayed. Suppose flights are randomly selected one at a time from all flights. Assume each selection is independent of another. Which of the following is closest to the probability that it will take 5 selections to find one flight that is delayed?

a. 0.0783
b. 0.0921
c. 0.4780
d. 0.5220
e. 0.5563

Answer 1

a. 0.0783

Explanation:

For each flight, we have these following probabilities:

A 15% probability that a flight is delayed

An 85% probability that a flight is on time.

Which of the following is closest to the probability that it will take 5 selections to find one flight that is delayed?

This is the probability that the first four flights are on time and the fifth is late. So

`P = 0.85*0.85*0.85*0.85*0.15 = 0.0783`

So the correct answer is

a. 0.0783