14.0_ChiSquare.Rmd

# Chi-square: Contingency Tables and Goodness of Fit {#ch.chisq}

## Learning Objectives for Chapter

Jen's:
1. Construct a contingency table and calculate its degrees of freedom.
2. State if a larger or smaller chi square value indicates stronger dependency between variables in a test of independence.
3. Describe the theory behind how we calculate the expected values in a test of independence.


1. Define independence between random variables.
1. Identify problems that can be addressed as goodness of fit or independence tests.
1. Define degrees of freedom for the $\chi^2$ distribution.
1. Test for independence of categorical random variables.
1. Test the goodness of fit of theoretical distributions to data.
1. Look up quantiles and probabilities for the $\chi^2$ distribution.

## Origin of the $\chi^2$ distribution

## Exercises and Solutions

## Homework Problems

## Lab Project