A standard deviation is a statistic that measures the dispersion of a data set relative to its mean. In addition, it is calculated as the square root of variance. What is a standard deviation? … A standard deviation is a statistical measurement. that highlights that individual data points of a data set are deviated from their mean. In addition, if the data point is away from its mean, there is a high deviation or volatility. and if the data point is near its mean, which means low volatility or low deviation from its mean. Moreover, it is calculated as the …