Use the normal approximation to the binomial distribution to answer this question. Fifteen percent of all students at a large university are absent on Mondays. If a random sample of 12 names is called on a Monday, what is the probability that four students are absent?
A)0.0683
B)0.0213
C)0.0021
D)0.1329

Question

Quizplus · Accepted Answer

The probability of a student being absent on Monday is 0.15. The probability of a student being present on Monday is 0.85. The mean of the binomial distribution is np = 12 * 0.15 = 1.8. The standard deviation of the binomial distribution is sqrt(np(1-p)) = sqrt(12 * 0.15 * 0.85) = 1.02. The probability of four students being absent is P(X = 4) = 0.0683.

Use the Normal Approximation to the Binomial Distribution to Answer