Chapter 2
Problem 9 (4 points)
A pharmaceutical company conducted a study to evaluate the effect of an allergy relief medicine; 250 patients
with symptoms that included itchy eyes and a skin rash received the new drug. The results of the study are as
follows: 90 of the patients treated experienced eye relief, 135 had their skin rash clear up, and 45 experienced
relief of both itchy eyes and the skin rash. What is the probability that a patient who takes the drug will
experience relief of at least one of the two symptoms?

Problem 15 (14 points)
During a recent period of high unemployment, hundreds of thousands of drivers dropped their automobile
insurance. Sample data representative of the national automobile insur- ance coverage for individuals 18 years
of age and older are shown here.
a.
Develop a joint probability table for these data and use the table to answer the remaining
questions.

b.
What do the marginal probabilities tell you about the age of the U.S. population
?

P(B) is 0.54.
46% are 18 to 34 years of age and 54% are 35 years and over.
c.
What is the probability that a randomly selected individual does not have automobile insurance
coverage?

d.
If the individual is between the ages of 18 and 34, what is the probability that the individual does
not have automobile insurance coverage? e.
If the individual is age 35 or over, what is the
probability that the individual does not have automobile insurance coverage?