According to the MIT Airline Data Project, American Airlines controlled 15.5% of the domestic market during a recent year. A random sample of 125 domestic passengers that year was selected. Using the normal approximation to the binomial distribution, what is the probability that 20, 21, 22, 23, 24, or 25 passengers from this sample were on American Airline flights?

Question

Quizplus · Accepted Answer

The probability of a passenger being on an American Airline flight is 0.155. The probability of 20, 21, 22, 23, 24, or 25 passengers from a sample of 125 being on American Airline flights can be calculated using the normal approximation to the binomial distribution:P(20 ≤ X ≤ 25) = P(19.5 < X < 25.5) = Φ(25.5) - Φ(19.5) = 0.4225Therefore, the probability is 0.4225, which corresponds to choice A.

According to the MIT Airline Data Project, American Airlines Controlled