# Exploring Bayes' Theorem

- Author:
- David Radcliffe

This GeoGebra worksheet can be used to explore the following problem, which is a classic application of Bayes' theorem: If a person tests positive for a disease, what is the probability that he or she is actually infected?
The user can enter the following quantities by using the input boxes or the sliders:

**Incidence**is the percentage of the general population that is infected.**False positive rate**is the probability that a person who is not infected will test positive for the disease.**False negative rate**is the probability that a person who is infected will test negative for the disease. The pie chart shows the conditional probability that a person is infected given that he or she tests positive for the disease.