# Standard Deviation

### Introduction

The standard deviation is a statistical measure of the precision in a series of repetitive measurements. It is calculated from:

Where s in standard deviation, N is the number of datum, x_{i}
is each individual measurement, and x bar is the mean of all
measurements. The value x_{i} - x bar is called the residual for each measurement.

### Related topics:

### Further Information

/chem-ed/data/std-dev.htm, updated 10/14/96

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