In statistics, the standard deviation is the square root of the variance; it's one way of showing how data varies, or how it is spread out in a distribution. The standard deviation tells you how much of the data lies within a certain area. A standard deviation can be tricky to calculate by hand, as it requires multiple steps. The TI84 Plus graphing calculator can eliminate those steps and calculate the standard deviation in just a few keystrokes.

### Step 1

Click on the "2nd" key and then click on "0." This selects the catalog.

### Step 2

Press the "LN" button to scroll through the catalog to the letter "s."

### Step 3

Press the "down arrow" key to scroll until you reach "stdDev(." Press "Enter."

### Step 4

Complete the statement with an open curly bracket -- the "{" sign -- and the numbers for which you want to find the standard deviation, followed by a closing curly bracket and closing parenthesis. For example: stdDev({1,2,3,4,5,6}).

### Step 5

Press the "Enter" key. The calculator will return the standard deviation for the entered numbers.