Mistake Master
All five units of the redesigned AP Statistics course framework, with exam weighting and topic counts. College Board redesigned AP Statistics starting with the 2026-27 school year; the first exam in the new format is May 2027, and most older prep materials still follow the retired 9-unit course. Weightings are from the College Board Course and Exam Description (see also the reference sheet).
Displaying and describing quantitative and categorical data, summary statistics, the normal distribution, and how data gets collected: sampling methods, bias, experiments versus observational studies, and scope of inference. The heaviest unit on the exam.
Probability rules, conditional probability and independence, random variables, and the binomial setting, building to sampling distributions: the bridge from describing data to drawing conclusions from it.
The full inference toolkit for proportions: sampling distributions, confidence intervals and significance tests for one and two proportions, errors and power, and chi-square tests for categorical data.
Confidence intervals and significance tests for one and two means with the t distribution, paired versus independent designs, and verifying conditions before computing anything.
Scatterplots, correlation, least-squares regression, residuals, and inference for the slope: describing and testing linear relationships between two quantitative variables.
All five units, mixed together. Sit a 42-question run that matches the length of the AP Statistics multiple-choice section and mirrors its unit weighting, so Unit 1 shows up about as often as it does on the real thing. Every wrong answer is filed under the misconception behind it, and the five you missed most come back below as drill links.
All five units are live, with a lesson, a topic diagnostic and targeted drills for every one of the 55 topics, built on the course's 65 misconception codes, plus a cumulative for each unit and for the whole course.