Median is middle value when data sorted. For n values: If n odd, median = ((n+1)/2)th value. If n even, median = average of (n/2)th and (n/2 + 1)th values. Example: {2, 4, 6, 8, 10} → median = 6 (3rd of 5). {2, 4, 6, 8} → median = (4+6)/2 = 5. For grouped data: Median = L + [(n/2 - F)/f] × w, where L = lower class of median class, F = cumulative frequency before median class, f = frequency of median class, w = class width. Advantages: Not affected by outliers; easy to understand. Disadvantages: Ignores most data values. Exam tip: Use when data skewed or has outliers. Compare median with mean for distribution shape.