A statistics professor has stated that 90% of his students pass the class. To check this claim, a random sample of 150 students indicated that 129 passed the class. If the professor's claim is correct, what is the probability that 129 or fewer will pass the class this semester?
A) 0.9484
B) 0.5516
C) 0.4484
D) 0.0516

Question

Quizplus · Accepted Answer

The probability can be calculated using the normal approximation to the binomial distribution. With a sample size of 150 and a success probability of 0.9, the mean is 135 and the standard deviation is approximately 3.674. Using the normal distribution, the probability of 129 or fewer passing is approximately 0.0516.

A Statistics Professor Has Stated That 90% of His Students