In this part we cover classical tests such as the t-test for the mean and the χ2-test for the population variance. We assume throughout this part that the underlying distribution is Gaussian. Chapter 2 covers tests for the questions if a mean equals a specific value or if two populations share the same mean. Chapter 3 presents statistical tests on variances of one or two normal populations. In both chapters it must be ascertained whether the accompanying parameters (the variance for the mean tests and the mean for the variance tests) are known or unknown. In the two sample cases it is also necessary to determine whether the two samples are independent or not.