1. Each of 4 people is presented with gourmet coffee and ordinary coffee and asked to identify the gourmet coffee. None of the 4 can really tell the difference and are merely guessing.

Question

a. What is the probability that exactly 2 of the 4 correctly identify the gourmet coffee?

b. What is the probability that at least 2 of the 4 correctly identify the gourmet coffee?

c. What is the probability that at most 1 out of the 4 correctly identify the gourmet coffee?

Answer 1

Use a binomial probability table or a formula like the following:

P(x) = (nCx)(p^x)[q^(n-x)]

For a): Find P(2)
For b): Find P(2), P(3), and P(4). Add together for your probability.
For c): Find P(0) and P(1). Add together for your probability.