Question

Consider the following binomial experiment. The probability that a green jelly bean is chosen at random from a large package of jelly beans is 2/5. If Sally chooses 12 jelly beans, what is the probability that at most two will be green jelly beans?

a) 0.5000

b) 0.4100

c) 0.0654

d) 0.9166

e) 0.0834

f) None of the above.

Answer 1

Let X be a number of green jelly beans among 12 jelly beans.

P(green jelly beans) = 2/5 = 0.40

X ~ Binomial (n = 12, p = 0.40)

We want to find, the probabilitiy that at most two will be green jelly beans. That is to find, P(X ≤ 2)

=> P(X ≤ 2) = 0.0834

Answer : e) 0.0834