Ch 4 · Measures of Central Tendency & Dispersion

📘 Core concepts

1. 1Mean: arithmetic average; sensitive to extremes.
2. 2Median: middle value of ordered data; robust to outliers.
3. 3Mode: most frequent value.
4. 4Dispersion measures: range, mean deviation, standard deviation, variance.
5. 5Empirical relation: Mode = 3 Median − 2 Mean (for moderately skewed).