Summary Statistics
n = 10 · mean 22.7 · median 22 · σ 6.649
Histogram (frequency distribution)
Box plot (5-number summary)
Step-by-step calculation
Formula
Mean = Σx/n. Variance = Σ(x − mean)²/n. Std dev = √variance. Median = middle value (or mean of two middle values when n is even). Q₁/Q₃ = 25th/75th percentiles.
- 1n = 10 values, sorted: [12, 15, 18, 20, 22, 22, 25, 28, 30, 35]
- 2Sum = 227. Mean = 227 / 10 = 22.7.
- 3Median (middle pair averaged) = 22.
- 4Mode = 22 (each appears 2 times).
- 5Variance σ² = mean of squared deviations from the mean = 44.21.
- 6Standard deviation σ = √variance = 6.649 — typical distance from the mean.
- 7Q₁ = 18.5, Q₃ = 27.25, IQR = Q₃ − Q₁ = 8.75 (middle-50% spread).
- 8Note: this calculator uses POPULATION variance (divide by n). Sample variance (divide by n−1) would give 49.122.