Standard Deviation

Standard Deviation Definition

The term "standard deviation" (or σ) refers to a measurement of the data's dispersion from the mean. A low standard deviation implies that the data are grouped around the mean, whereas a large standard deviation shows that the data are more dispersed.

In contrast, a high or low standard deviation indicates that the data points are, respectively, above or below the mean. A standard deviation that is close to zero implies that the data points are close to the mean. In the illustration, the curve at the top is more dispersed and has a higher standard deviation than the curve at the bottom, which is more concentrated around the mean and has a lower standard deviation.

You can use the following formula to determine the standard deviation:

Important Notes on Standard Deviation:

• The square root of the average of the squared differences of data observations from the mean is called the standard deviation.
• Standard deviation is the positive square root of variance.
• Standard deviation is the indicator that shows the dispersion of the data points about the mean.