According to the American Lung Association, 90% of adult smokers started smoking before turning 21 years old. Ten smokers 21 years old or older are randomly selected, and the number of smokers who started smoking before 21 is recorded.
(a) Explain why this is a binomial experiment.
(b) Find and interpret the probability that exactly 8 of them started smoking before 21 years of age.
(c) Find and interpret the probability that fewer than 8 of them started smoking before 21 years of age.
(d) Find and interpret the probability that at least 8 of them started smoking before 21 years of age.
(e) Find and interpret the probability that between 7 and 9 of them, inclusive, started smoking before 21 years of age.