# Lesson 38: Tests About One Mean

### Introduction

In this lesson, we'll continue our investigation of hypothesis testing. In this case, we'll focus our attention on a hypothesis test for a population mean *μ* for three situations:

- a hypothesis test based on the normal distribution for the mean
*μ*for the completely unrealistic situation that the population variance*σ*^{2} - a hypothesis test based on the
*t*-distribution for the mean*μ*for the (much more) realistic situation that the population variance*σ*^{2} - a hypothesis test based on the
*t*-distribution for*μ*, the mean difference in the responses of two dependent populations_{D}