Which statement about t-tests and comparing means is correct?

Which statement about t-tests and comparing means is correct?

• A. A t-test can compare more than two means.
• B. A t-test is inappropriate for comparing more than two means.
• C. A t-test compares medians rather than means.
• D. A t-test requires nonparametric data.

Answer: (B)

A t-test is designed to compare the means of two groups. It is not appropriate for comparing more than two means because testing multiple two-group differences separately inflates the chance of a false positive. For more than two groups, the standard approach is ANOVA, which tests whether at least one group mean differs from the others; if ANOVA is significant, you then follow up with post hoc tests to identify which pairs of groups differ. This statement is the best answer because it directly reflects how t-tests are intended to be used. Remember that t-tests assess means, not medians, and they are parametric tests that assume normality (and, for two-sample tests, often equal variances). If those assumptions aren’t met, nonparametric alternatives (like Mann-Whitney U for two groups or Kruskal-Wallis for more than two groups) are considered.

A t-test is designed to compare the means of two groups. It is not appropriate for comparing more than two means because testing multiple two-group differences separately inflates the chance of a false positive. For more than two groups, the standard approach is ANOVA, which tests whether at least one group mean differs from the others; if ANOVA is significant, you then follow up with post hoc tests to identify which pairs of groups differ.

This statement is the best answer because it directly reflects how t-tests are intended to be used. Remember that t-tests assess means, not medians, and they are parametric tests that assume normality (and, for two-sample tests, often equal variances). If those assumptions aren’t met, nonparametric alternatives (like Mann-Whitney U for two groups or Kruskal-Wallis for more than two groups) are considered.