Which test compares the means of two independent groups to determine if they are significantly different?

Which test compares the means of two independent groups to determine if they are significantly different?

• A. Paired t-test
• B. Independent t-test
• C. ANOVA
• D. Wilcoxon test

Answer: (B)

To determine if two separate groups differ in their average scores, you use the independent samples t-test. This test looks at the difference between the two group means and compares it to how much the scores vary within each group. If the difference is large relative to the within-group variability, the test yields a small p-value, suggesting the population means are not equal. Key ideas: the groups must be independent (no paired observations), the data are approximately normally distributed within each group (or you have a large sample), and the variances are similar across groups (though there’s a version that relaxes this last assumption). The independent samples t-test is specifically about means, making it the right tool for this situation. The other options don’t fit as cleanly. A paired t-test is for related or matched observations (same subjects measured twice or matched pairs). ANOVA handles three or more groups or more complex designs. The Wilcoxon option is a nonparametric alternative that compares medians rather than means and is used when data don’t meet normality assumptions.

To determine if two separate groups differ in their average scores, you use the independent samples t-test. This test looks at the difference between the two group means and compares it to how much the scores vary within each group. If the difference is large relative to the within-group variability, the test yields a small p-value, suggesting the population means are not equal.

Key ideas: the groups must be independent (no paired observations), the data are approximately normally distributed within each group (or you have a large sample), and the variances are similar across groups (though there’s a version that relaxes this last assumption). The independent samples t-test is specifically about means, making it the right tool for this situation.

The other options don’t fit as cleanly. A paired t-test is for related or matched observations (same subjects measured twice or matched pairs). ANOVA handles three or more groups or more complex designs. The Wilcoxon option is a nonparametric alternative that compares medians rather than means and is used when data don’t meet normality assumptions.