The List Editor App

How do I calculate the standard deviation of a list?

Standard deviation can be calculated by using the stdDev( function or as an output of the 1-Var stats calculation.

The stdDev( function can be located by performing the following:

1. Press a È.
2. Press the right arrow key › to MATH and select 7:stdDev(.

Follow the steps listed below to calculate standard deviation of a single list of data.

Example: To find the standard deviation of the data list, enter this data into L1.

L1: 2, 3, 5, 1, 4

1. Press a È, press right arrow › to MATH and press the down arrow key ≥ to select 7:stdDev(.
2. Press a Õ { 2 , 3 , 5 , 1 , 4 a } ).
3. Press =, and the sample standard deviation of the list will be displayed.

Alternatively, if a list is stored in the list editor, then you can use the 1-var stat calculation by pressing m and the right arrow key › to CALC, and then selecting option 1: 1-Var Stats. The output will contain both the sample standard deviation, s, and population standard deviation σ.

Example: Find the standard deviation of a list with associated counts.

L1: 2, 3, 5, 1, 4
L2: 1, 2, 5, 4, 1

1. Press a , È, press right arrow › to MATH, and then press the down arrow key ≥ to select 7:stdDev(.
2. Press =, and the standard deviation of the data in L1, using the counts in L2, will be displayed.