Percentile
Also called: percentile rank, quantile
A percentile is the value below which a given share of observations falls — the 90th percentile has 90% of the data beneath it. It's the natural language of risk: Value at Risk is a percentile of the loss distribution, and salary benchmarking and credit scoring are both percentile statements. Percentiles are robust to outliers, which is precisely why they're used where averages mislead.
Want more than a definition? Learn it in Stat Dojo →