## Introduction to Probability Models

Lecture 10

Qi Wang, Department of Statistics

Sep 13, 2017

## Example 1

Let us assume that a specific disease is only present in 5 out of every 1,000 people.
Suppose that the test for the disease is accurate 99% of the time a person has the disease
and 95% of the time that a person lacks the disease. Find the probability that a random person
will test positive for this disease.