Standard deviation: Difference between revisions
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imported>Doug Williamson (Expand to relate to Mean deviation.) |
imported>Doug Williamson (Add embedded link to Variance page.) |
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Standard deviation measures the spread of data around their mean. | Standard deviation measures the spread of data around their mean. | ||
The standard deviation is the square root of the variance. | The standard deviation is the square root of the [[variance]]. | ||
Standard deviation is used widely as a measure of risk, because it is relatively easy to calculate, and to compare and combine with the standard deviations of other variables. | Standard deviation is used widely as a measure of risk, because it is relatively easy to calculate, and to compare and combine with the standard deviations of other variables. | ||
Revision as of 10:14, 22 November 2015
(SD).
Standard deviation measures the spread of data around their mean.
The standard deviation is the square root of the variance.
Standard deviation is used widely as a measure of risk, because it is relatively easy to calculate, and to compare and combine with the standard deviations of other variables.
Its order of magnitude is the difference, ignoring the sign, between the mean and a randomly chosen item in the population.
