Ch 4 · Measures of Central Tendency & Dispersion

5 concept points · 6 formulas · 4 exam-critical points.

📘 Core concepts

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