About one in every five Canadian residents was born outside of Canada. If 12 Canadian residents are selected at random, what is the probability that 5 of them were born outside Canada?

Answer 1

Binomial probability of x successes in n tries, where success has probability p:

C (n,x) p^x (1-p)^(n-x)

x = birth status (inside/outside Canada)

x is a binomial variable

probability 1/5 = 0.2 born outside of Canada

Probability if 12 sampled, that 5 born out of Canada.

C(12,5) 0.2^5 0.8^7