The National Vaccine Information Center estimates that 90% of Americans have had
chickenpox by the time they reach adulthood.
We now consider a random sample of 120 American adults:
a)
Would you be surprised if there were 105 people who have had chickenpox in their
childhood?
b)
What is the probability that 105 or fewer people in this sample have had chickenpox
in their childhood? How does this probability relate to your answer to part (a)?
2 answers