In this video, Salman Khan of Khan Academy explains probability. Part 7 of 8.
Khan Academy

Gives explanation and exercises to learn the addition rule of probability
Algebra Lab

In this Early Edge video lesson, you'll learn more about Introduction to Algebra, so you can be successful when you take on highschool Math & Algebra.
The Princeton Review

In this Early Edge video lesson, you'll learn more about TwoStep Equations, so you can be successful when you take on highschool Math & Algebra.
The Princeton Review

In this video, Salman Khan of Khan Academy explains probability. Part 3 of 8.
Khan Academy

In this video, Salman Khan of Khan Academy explains probability. Part 2 of 8.
Khan Academy

This gives a general description of standard deviation.
Robert Niles

A web page with clear and concise explanations for combinations and permutations
Math is Fun!
