After reading this chapter, you should be able to do the following:

• Explain when a single-sample t should be used rather than a z for a sample mean
• Explain why the z for a sample mean is superior to the single-sample t test but rarely used
• Write one- and two-tailed null and research hypotheses using population parameters and words
• Compute the degrees of freedom and define the critical region for one- and two-tailed single-sample t tests
• Explain why a z for a sample mean test and a single-sample t test have different critical regions
• Compute a single-sample t by hand and using SPSS
• Determine whether or not you should reject the null hypothesis
• Compute and interpret an effect size (d)
• Interpret the SPSS output for a single-sample t
• Summarize the results of the analysis using American Psychological Association (APA) style