# 9.3: Introduction to Distribution of Differences in Sample Proportions


## What you’ll learn to do: Recognize when to use a two population proportion hypothesis test to compare two populations/treatment groups.

In this section we will recognize when to use a hypothesis test or a confidence interval to compare two populations or to investigate a treatment effect for a categorical variable. It is important to determine if a study involving two proportions is an experiment or an observational study. We will also learn to describe the sampling distribution of the difference between proportions as well as draw conclusions about a difference in population proportions from a simulation.