# Learning Objectives

• Explain why a t distribution is associated with n – 1 degrees of freedom and describe the information that is conveyed by the t statistic.
• Calculate the degrees of freedom for a one–sample and a two–independent sample t test, and locate critical values in the t table.
• Identify the assumptions for the one-sample t test.
• Compute a one-sample t test and interpret the results.
• Compute effect size and proportion of variance for a one–sample t test.
• Identify the assumptions for the two–independent sample t test.
• Compute a two–independent sample t test and interpret the results.
• Compute effect size and proportion of variance for a two–independent sample t test.
• Summarize the results of a one–sample and a two–independent sample t test in APA format.
• Compute a one–sample and a two–independent sample t test using SPSS.