Summary
The chapter on the chi-square distribution introduces various chi-square tests used in hypothesis testing for categorical data. Key topics include identifying when to use the goodness-of-fit test versus tests of independence and homogeneity, calculating the chi-square statistic using observed and expected frequencies, and determining degrees of freedom based on the structure of your data. Most chi-square tests are right-tailed, meaning that larger test statistic values indicate a greater discrepancy between observed and expected values, leading to rejection of the null hypothesis if the p-value is sufficiently small.