Question

2. Dee Pressants owns Dee’s Pharmacy located in a small medical office building. Dee estimates that 20% of her prescription business comes from referrals from Dr. Mel Practice. For the next 25 prescription customers, what is the probability that a. 6 or less were referred by Mel? b. Between 3 and 6 were referred by Mel? c. At least 4 were referred by Mel? d. Exactly 5 were referred by Mel? e. Dee makes $10 profit per prescription but has to pay Mel a $3 kickback on any referrals. What is the expected profit from the 25 customers?

Answer 1

The probability that a randomly selected prescription business comes from referrals from Dr. Mel Practice = 0.2

Let X denotes the number of prescription customers who were referred by Mel among next 25 prescription customers.

X ~ Binomial(n = 25, p = 0.2)

The probability mass function of X is

a) The probability that 6 or less were referred by Mel

b) The probability that at least 4 were referred by Mel

.

+6+3., /

d) The probability that exactly 5 were referred by Mel

e) The expected number of prescription customers who were referred by Mel among next 25 prescription customers

The expected profit from the 25 customers