Question

In a large bag of marbles, 30% of them are red. a child chooses 4 marbles from this bag. if the child chooses the marbles at random, what is the chance that the child gets exactly three red marbles? 0.0756 0.1764 0.2646 0.0810

Answer 1

Use the binomial distribution with n = 4, p = 0.3, q = 0.7 , formula

P[k] = nCk * p^k *q^(n-k)

P[3] = 4c3 * 0.3^3 * 0.7 = 0.0756