Quantiles, Percentiles & Z-Score Standardization

Practice quantiles, percentiles & z-score standardization through 25 original single-select and multiselect questions. Build from core understanding and calculations to interpretation, counterexamples and method selection. Prerequisites: arithmetic, percentages, ordered data and the preceding foundations topics. Interpret standardized distances; Calculate and reverse z-scores; Apply explicit percentile-rank tie conventions; Compute quantiles with specified interpolation; Distinguish sample and population standardization; Evaluate comparability, direction and reference choice. Worked solutions explain the reasoning and each distractor. Quantile, trimming and variance conventions are stated where needed. Sources include NIST and established statistical documentation. Cover photograph: Lukas Blazek / Pexels.