Approximate Binomial Probabilities Using the Normal Distribution
-A local concert center reports that it has been experiencing a 15% rate of no-shows on advanced reservations. Among 150 advanced reservations, find the probability that there will be fewer than 20 no-shows.
A) 0.2451
B) 0.7549
C) 0.7967
D) 0.3187

Question

Quizplus · Accepted Answer

The correct answer is A because the probability of fewer than 20 no-shows can be approximated by the normal distribution with mean 150 * 0.15 = 22.5 and standard deviation sqrt(150 * 0.15 * 0.85) = 4.08. Using a standard normal table, the probability of fewer than 20 no-shows is approximately 0.2451.