# Lesson 11: Chi-Square Tests

In this lesson we will learn how to compare the proportions of more than two independent groups and how to test for a relationship between two categorical variables. In this lesson you will also review risk and learn about relative risk.

### Lesson 11 Learning Objectives

Upon completion of this lesson, you should be able to:

- identify research questions that may be addressed using a chi-square goodness-of-fit test or chi-square test of independence.
- conduct a chi-square goodness-of-fit test.
- conduct a chi-square test of independence.
- calculate and interpret relative risk.

Before we begin, let's review the various classifications of variables from Lesson 1:

** Categorical**: Names or labels without a meaningful order of magnitudes, also known as qualitative

** Quantitative**: Numerical values with magnitudes that can be placed in a meaningful order, also known as numerical

In this lesson we will be examining methods for analyzing **categorical **variables.