Question

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 most two of the expectant mothers will have a Caesarean delivery? 0.5783 0.2696 0.4217

Answer 1

Let , X be the number of mothers will have a Caesarean delivery.

Here , X ahs binomial distribtuion with parameter n=7 and p=0.33

Therefore , teh PMF of X is ,

; x=0,1,2,....,n and q=1-p

= 0 ; otherwise

Now ,

Therefore , the probability that at most two of the expectant mothers will have a Caesarean delivery is 0.5783