Answer: 29

The correct answer is **B (29)**. **Explanation:** - For a paired comparisons test, the t-statistic has \( n - 1 \) degrees of freedom, where \( n \) is the number of paired observations. - Here, \( n = 30 \), so the degrees of freedom are \( 30 - 1 = 29 \). **Why not A or C?** - **A (28)** is incorrect because it assumes \( n - 2 \) degrees of freedom, which is not applicable for a paired test. - **C (58)** is incorrect because it represents the degrees of freedom for a hypothesis test concerning the equality of means of two independent samples, calculated as \( n_1 + n_2 - 2 \).

Author: LeetQuiz Editorial Team