These study tips are designed to clarify key points and help you to avoid errors that students commonly make. Review the Tips for Success as you study each chapter and review them again after you have studied each chapter.

1. It is important that you understand Chapter 4 quite solidly before going on to this chapter.
2. Before moving on to later chapters in the book, ensure that you fully understand the idea of a distribution of means (and why it is the appropriate comparison distribution when a sample contains more than one individual). You may need to go through the chapter a couple of times in order to achieve full understanding of this crucial concept.
3. When you figure the variance of a distribution of means (σ²_M), be sure to divide the population variance (σ²) by the number of individuals in each sample. In many of the examples, you are told the population standard deviation (σ), which you will first have to square to find the population variance (σ²); then you can use formula 5-2 to find the variance of the distribution of means (σ²_M).
4. Be sure you fully understand the different types of distributions shown in Table 5-1 (p. 159) before you move on to later chapters. To check your understanding, cover up portions of the table and then try to recall the hidden information. Also, don’t be confused: There happen to be three kinds of distributions, but they do not have any one-to-one link – the rules are about the relations among the different distributions.
5. As in Chapter 4, Population 2 is the population for the comparison distribution, which is the distribution that represents the population situation if the null hypothesis is true.