Approximately 5% of children develop chronic bronchitis in the first year of life. In a group of 20 children, find the probability that exactly 2 of them develop chronic bronchitis in the first year of life.
Formula:
P(x) = (nCx)(p^x)[q^(n-x)]
Your data:
x = 2
p = .05
q = 1 - p = 1 - .05 = .95
n = 20
Substitute and calculate for your probability.