This free textbook from OpenIntro, a nonprofit publisher of open educational resources, is built around the AP Statistics curriculum and is widely used in high school classrooms and two-year colleges. The fourth edition, released in 2026, organizes the material into five chapters that follow the arc of a typical AP course, from describing and collecting data through probability, inference, and regression.
The book sits at the center of a larger set of teaching materials. OpenIntro publishes chapter-by-chapter videos, slides, and labs to go with it, with lab versions for R (both base R and the tidyverse) and several other tools, along with calculator guides for Desmos, TI-83/84, Casio, and NumWorks. A separate guide maps the fourth edition’s content to the AP Statistics curriculum, and verified teachers can request exercise solutions and an exam question bank.
Topics in the fourth edition include:
- Exploring categorical and numerical data with graphs and summaries
- Sampling methods, sources of bias, and experimental design
- Probability rules, conditional probability, and random variables
- Binomial and normal distributions, sampling distributions, and the Central Limit Theorem
- Confidence intervals and hypothesis tests for one and two proportions
- Chi-square tests for goodness of fit and two-way tables
- Inference for means, including paired data and two independent samples
- Summarizing bivariate numerical data and fitting least squares regression lines
The PDF is free to download, including a version designed for screen readers, and low-cost black-and-white and full-color paperbacks are also available.
Find out more about the book and the supplementary resources at openintro.org/book/ahss.