# Standard Deviation To calculate the standard deviation you take the square root of the [[Variance]] $\sigma = \sqrt\frac{\sum(x-\bar x)^2}{n-1}$ The standard deviation is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the [[Mean]] of the set, while a high standard deviation indicates that the values are spread out over a wider [[Range]]. The standard deviation is sensitive to outliers but it is a very useful value to have. # Code ```r sd(x) ```