Suppose that

Question

30%

of all college students smoke cigarettes. A sample of
18
is selected randomly. What is the probability that exactly
10

students smoke? Round your answer to four decimal places.

Answer 1

http://onlinestatbook.com/2/probability/binomial.html
C(18,10) = 18!/[10!(18-10)]
P(18) = C(18,10) * .3^10 * .7*8

Answer 2

http://www.statisticshowto.com/binomial-distribution-formula/