Statistics and Probability

This website provides training and tools to help you solve statistics problems quickly, easily, and accurately - without having to ask anyone for help.

Online Tutorials

Learn at your own pace. Free online tutorials cover statistics, probability, regression, survey sampling, and matrix algebra - all explained in plain English.

Practice and review questions follow each lesson. Online calculators take the drudgery out of computation. Perfect for self-study.

AP Statistics

Here is your blueprint for test success on the AP Statistics exam.

  • AP Tutorial: Study our free, AP statistics tutorial to improve your skills in all test areas.
  • Practice exam: Test your understanding of key topics, through sample problems with detailed solutions.
  • Study guide: Read our review of the most popular AP study guides, and choose the right guide for you.
  • Calculator: Compare AP-approved graphing calculators, based on price and user ratings.
  • A quick overview: Why you should take AP statistics, what is required to pass, and how Stat Trek can help.

Be prepared. Get the score that you want on the AP Statistics test.

Random Number Generator

Produce a list of random numbers, based on your specifications.

  • Control list size (generate up to 1000 numbers).
  • Specify the range of values that appear in your list.
  • Permit or prevent duplicate entries.

Free and easy to use.

Random number generator

Sample Size Calculator

Create powerful, cost-effective survey sampling plans.

  • Find the optimum design (most precision, least cost).
  • See how sample size affects cost and precision.
  • Compare different survey sampling methods.
  • Assess statistical power and Type II errors.

Tailor your sampling plan to your research needs.

Sample Size Calculator

Stat Toolbox

Check out our statistical tables and online calculators - fast, accurate, and user-friendly.

Each calculator features clear instructions plus answers to frequently-asked questions.