if 30% of children age 2-6 have high cholesterol, and 12 are analyze what is the probability that exactly 3 have high cholesterol

Question

Biostatistics

Answer 1

This is a binomial probability question.  p = 0.30, q = 1-p = 0.70, and n = 12.

Probability (exactly 3) = (12 C 3) (0.30^3) (0.70^9)

12 C 3 = 12! / (9! 3!) = (10*11*12) / 3! = 220

220 * 0.027 * 0.040 = 0.240.