# Know your AP Stats Formula Sheet

Updated: Sep 12

The __AP Stats formula sheet__ can do one of two things to a student:

1. Provide a sense of comfort and security, like a warm blanket.

2. Terrify them because they have no idea what half of the formulas are!

The key is for students to be familiar with the formula sheet BEFORE the exam. Ideally, students won't need to reference the formula sheet often, but if they do, it's important they can find the formulas they need quickly.

Check out this video that walks students through the formula sheet. This video is part of the Stats Medic AP Statistics Exam Review Course.

## Be familiar with the notation on the formula sheet

For the binomial formula (n x) means "n choose x" and is equivalent to nCx (combinations).

For probability, "U" means union and can be replaced with "OR"

For probability, "upside down U" means intersection and can be replaced with "AND"

## Important formulas that are NOT on the formula sheet.

1. Formulas for mean and standard deviation when combining random variables (one does not simply add standard deviations).

2. Expected counts for chi-square tests.