Overview of statistical methods:
| Categorical data | Numerical data | |
|---|---|---|
| inference about one population | confidence interval for p. z test for one proportion p. goodness-of-fit test | confidence interval for μ. t test for mean |
| inference about two populations | confidence interval for p₁ - p₂ Z test for two proportions | t test for matched pairs t test for independent samples |
| relationship between two variables | chi-square test of independence Fisher’s exact test | t test of correlation simple linear regression |
| comparing more than 2 populations | chi-square test for homogeneity |