Probability and Statistics - Revision history

DavidB4-bot: /* top */clean up & uniformity

2016-07-13T17:52:34Z

‎top: clean up & uniformity

AndrewLe: remove redundant category

2014-08-05T22:59:03Z

remove redundant category

Qwestor: New page: {{math-h}} '''Variance''' is a measure in statistics of the dispersion of a set of values (represented as $X$ ). It is defined as : $\sigma^2 = \operat...$

2009-01-19T14:59:29Z

New page: {{math-h}} '''Variance''' is a measure in statistics of the dispersion of a set of values (represented as <math>X</math>). It is defined as :<math>\sigma^2 = \operat...

New page

{{math-h}}

'''Variance''' is a measure in [[Statistics|statistics]] of the [[dispersion]] of a set of values (represented as <math>X</math>). It is defined as

:<math>\sigma^2 = \operatorname{E}[(X-\operatorname{E}[X])^2] = \operatorname{E}[X^2] - (\operatorname{E}[X])^2</math>

where the [[expectation (math)|expected value]] of ''X'' is E(''X'').

The formula for variance must not be confused with the formula

:<math>S_{n}^2 = {\sum_n(x - \bar x)^2 \over n - 1}</math>

which is the formula for a [[point estimate]] of the true variance from a sample of size ''n''. As such this estimator itself has a variance which, as the formula indicates, decreases as the sample size increases.

[[category:Probability and Statistics]]
[[Category:Mathematics]]

← Older revision		Revision as of 22:59, August 5, 2014
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	[[category:Probability and Statistics]]		[[category:Probability and Statistics]]
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 {{math-h}}
-'''Variance''' is a measure in [[Statistics|statistics]] of the [[dispersion]] of a set of values (represented as <math>X</math>).  It is defined as
+'''Variance''' is a measure in [[statistics]] of the [[dispersion]] of a set of values (represented as <math>X</math>).  It is defined as
 :<math>\sigma^2 = \operatorname{E}[(X-\operatorname{E}[X])^2] = \operatorname{E}[X^2] - (\operatorname{E}[X])^2</math>
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-[[category:Probability and Statistics]]
+[[Category:Probability and Statistics]]

Probability and Statistics - Revision history

DavidB4-bot: /* top */clean up & uniformity

AndrewLe: remove redundant category

Qwestor: New page: {{math-h}} '''Variance''' is a measure in statistics of the dispersion of a set of values (represented as X). It is defined as :\sigma^2 = \operat...

Qwestor: New page: {{math-h}} '''Variance''' is a measure in statistics of the dispersion of a set of values (represented as $X$ ). It is defined as : $\sigma^2 = \operat...$