Mean, Median, Mode & Weighted Averages

Practice mean, median, mode & weighted averages 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. Calculate arithmetic means and totals; Find medians with explicit order and count; Distinguish unique, multiple and absent modes; Use frequency and grouped-data weights; Combine groups and update summaries; Diagnose insufficient information and weighting errors. 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.