STDEVPA function
Calculates standard deviation based on the entire population given as arguments, including text and logical values. The standard deviation is a measure of how widely values are dispersed from the average value (the mean).
Syntax
STDEVPA(value1,value2,...)
Value1, value2, ... are 1 to 255 values corresponding to a population. You can also use a single array or a reference to an array instead of arguments separated by commas.
Remarks

STDEVPA assumes that its arguments are the entire population. If your data represents a sample of the population, you must compute the standard deviation by using STDEVA.

For large sample sizes, STDEVA and STDEVPA return approximately equal values.

The standard deviation is calculated using the "n" method.

Arguments can be the following: numbers; names, arrays, or references that contain numbers; text representations of numbers; or logical values, such as TRUE and FALSE, in a reference.

Text representations of numbers that you type directly into the list of arguments are counted.

Arguments that contain TRUE evaluate as 1; arguments that contain text or FALSE evaluate as 0 (zero).

If an argument is an array or reference, only values in that array or reference are used. Empty cells and text values in the array or reference are ignored.

Arguments that are error values or text that cannot be translated into numbers cause errors.

If you do not want to include logical values and text representations of numbers in a reference as part of the calculation, use the STDEVP function.

STDEVPA uses the following formula:
where x is the sample mean AVERAGE(value1,value2,…) and n is the sample size.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example

Create a blank workbook or worksheet.

Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help

Press CTRL+C.

In the worksheet, select cell A1, and press CTRL+V.

To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

