Which test assesses variability between two groups to evaluate precision?

• A. F test
• B. T test
• C. Chi-Square test
• D. ANOVA

Answer: (A)

Precision is about how tightly repeated measurements cluster, i.e., the variability (variance) of results. To determine if two groups have the same level of precision, you compare their variances. The F-test is built for this purpose: it uses the ratio of the two sample variances and assesses, via the F-distribution, whether the observed ratio could occur if the true variances were equal.

A t-test looks at whether the group means differ, not their spread. Chi-square tests are for categorical data—assessing relationships or goodness-of-fit. ANOVA compares means across more than two groups. So when the goal is to evaluate precision between two groups, the F-test is the appropriate choice.