standard deviation

noun

Statistics.

1. a measure of dispersion in a frequency distribution, equal to the square root of the mean of the squares of the deviations from the arithmetic mean of the distribution.

standard deviation

noun

1. statistics a measure of dispersion obtained by extracting the square root of the mean of the squared deviations of the observed values from their mean in a frequency distribution

standard deviation

1. 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.

standard deviation

1. In statistics, a measure of how much the data in a certain collection are scattered around the mean. A low standard deviation means that the data are tightly clustered; a high standard deviation means that they are widely scattered.

About sixty-eight percent of the data are within one standard deviation of the mean.

Word History and Origins

Origin of standard deviation¹

First recorded in 1920–25

Example Sentences

That says the amount of a risky asset you want in your portfolio is equal to its expected excess return, divided by the square of the standard deviation of returns.

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The magnitudes of the changes were calculated in terms of standard deviations, which are used in statistics to convey how tightly a group of data points is clustered together.

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"Our study proposed a simple yet objective method for determining hotspots using standard deviation values. This is the first time that this has been done."

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Above eight standard deviations is considered “very high.”

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Funds' bonds allocation in November soared 18 points over the month to leave them net 19% overweight - almost 3 standard deviations above long-term averages.

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