# Standard-deviation meaning

stăndərd
A statistic used as a measure of the dispersion or variation in a distribution or set of data, equal to the square root of the arithmetic mean of the squares of the deviations from the arithmetic mean.
noun
(statistics) A measure of variability equal to the square root of the arithmetic average of the squares of the deviations from the mean in a frequency distribution.
noun
A statistic used as a measure of the dispersion or variation in a distribution, equal to the square root of the arithmetic mean of the squares of the deviations from the arithmetic mean.
In statistics, the average amount a number varies from the average number in a series of numbers.
The degree that a single value in a group of values varies from the mean (average) of the distribution. Standard deviation is a statistical measure that uses past performance of an investment or portfolio to determine the potential range of future performance and assess the probability of that performance. Standard deviations can be calculated for an individual security or for the entire portfolio.