Answer: Harmonic mean

## Explanation The **harmonic mean** helps reduce the impact of large outliers but not small outliers because: - **Median**: Resistant to both large and small outliers since it depends only on the middle value(s) - **Arithmetic mean**: Sensitive to both large and small outliers - **Harmonic mean**: Calculated as the reciprocal of the arithmetic mean of reciprocals: \( H = \frac{n}{\sum_{i=1}^{n} \frac{1}{x_i}} \) Large outliers have small reciprocals, which reduces their impact on the harmonic mean. However, small outliers have large reciprocals, which increases their impact. **Example**: For dataset [1, 2, 3, 100]: - Arithmetic mean = 26.5 (heavily influenced by 100) - Harmonic mean = 2.9 (less influenced by 100) - Median = 2.5 (unaffected by 100) For dataset [0.1, 2, 3, 4]: - Arithmetic mean = 2.275 - Harmonic mean = 0.56 (heavily influenced by 0.1) - Median = 2.5 (unaffected by 0.1)

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