70% of North American women have pierced ears. In a survey of 49 women, what is the probability that less than 30 had pierced ears?
A) 0.0901
B) 0.5901
C) 0.9099
D) 0.4099

Question

Quizplus · Accepted Answer

This is a binomial probability problem where n = 49, p = 0.70 (probability of having pierced ears), and we want the probability of x < 30 successes (women with pierced ears). Using the normal approximation to the binomial distribution (since n is large), we find the z-score for x = 29.5 (continuity correction) and calculate the probability. The correct calculation leads to a probability of 0.0901, making option A the correct answer.

70% of North American Women Have Pierced Ears