In section 8, we learn how to estimate population parameters (such as population mean, population proportion, and population variance) from sample data (such as sample mean, sample proportion, and sample variance). We start by learning about point estimates and how to produce unbiased estimators for population parameters. Then we learn about interval estimates (confidence intervals) to estimate population mean, population proportion, population variance.

In section 9, we learn about a very important statistical method (hypothesis testing) used to make wise decisions concerning population parameters. We learn two methods to perform hypothesis testing, the first is called the critical value approach and the second one is called the p-value approach.