What is the parametric test for comparing two independent samples?

• A. Unpaired samples t-test
• B. Paired samples t-test
• C. ANOVA
• D. Chi-square

Answer: (A)

For comparing the means of two independent groups with a parametric approach, the unpaired (independent samples) t-test is used. It assesses whether the difference between the two sample means is statistically significant, assuming the data in each group come from approximately normally distributed populations and have similar variances. This is ideal when the two groups are unrelated and the outcome is continuous. The paired t-test is for related or matched samples, such as before-and-after measures on the same subjects. ANOVA extends comparison to three or more groups (two groups could be analyzed with ANOVA, but the two-sample t-test is the direct choice). The chi-square test is for categorical data rather than comparing means.