In statistics, the Probability Distributions is the square root of the variance; It is a way to show how the data vary or how it is organized in a distribution. The Probability Distributions indicates how much of the data is within a certain area. A Probability Distributions can be difficult to calculate by hand since it requires several steps. The TI84 Plus graphing calculator can eliminate these steps and calculate the standard deviation with just a few keystrokes.

**Here are the Steps to calculate standard deviation:**

- Click on the “2nd” key and then click on “0”. This selects the catalogue.
- Press the “LN” button to scroll through the catalogue to the letter “s”.
- Press the “arrow down” key to scroll until you reach “stdDev (“.) Press “Enter.”
- Complete the statement with an open bracket (the “{“) sign and the numbers for which you want to find the standard deviation, followed by a closing bracket and a closing parenthesis. For example, stdDev ({1,2,3,4,5,6}).
- Press the “Enter” key. The calculator will return the standard deviation of the entered numbers.

### Advice

If an error occurs, be sure to enter the two sets of brackets to get your answer: T**he brackets are commonly overlooked.**