# STDEV function

Estimates standard deviation based on a sample. The standard deviation is a measure of how widely values are dispersed from the average value (the mean).

## Syntax

STDEV(number1,number2,...)

Number1,number2,...     are 1 to 30 number arguments corresponding to a sample of a population.

## Remarks

• Logical values such as TRUE and FALSE and text are ignored. If logical values and text must not be ignored, use the STDEVA function.

• STDEV assumes that its arguments are a sample of the population. If your data represents the entire population, then compute the standard deviation using STDEVP.

• The standard deviation is calculated using the "nonbiased" or "n-1" method.

• STDEV uses the following formula: ## Example

Suppose 10 tools stamped from the same machine during a production run are collected as a random sample and measured for breaking strength.

St1

St2

St3

St4

St5

St6

St7

St8

St9

St10

Formula

Description (Result)

1345

1301

1368

1322

1310

1370

1318

1350

1303

1299

=STDEV([St1], [St2], [St3], [St4], [St5], [St6], [St7], [St8], [St9], [St10])

Standard deviation of breaking strength (27.46391572)