According to a study by the Centers for Disease Control and Prevention, about 33% of U.S. births are Caesarean deliveries. Suppose seven expectant mothers are randomly selected. What is the probability that at least one of the expectant mothers will have a Caesarean delivery?
A) 0.0606
B) 0.2090
C) 0.9394
D) 0.9742

Question

Quizplus · Accepted Answer

The probability that at least one of the expectant mothers will have a Caesarean delivery can be found by subtracting the probability that none of them will have a Caesarean delivery from 1. The probability of not having a Caesarean delivery is 67% (100% - 33%). For seven mothers, this is (0.67)^7 ≈ 0.0606. Therefore, the probability of at least one Caesarean delivery is 1 - 0.0606 = 0.9394.

According to a Study by the Centers for Disease Control