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  1. Wikipedia
    https://en.wikipedia.org/wiki/Variance

    Variance - Wikipedia

    • In probability theory and statistics, variance is the expected value of the squared deviation from the mean of a random variable. The standard deviation (SD) is obtained as the square root of the variance. Variance is a measure of dispersion, meaning it is a measure of how far a set of numbers is spread out from their average value. It is the second central moment of a di… 展开

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    Definition

    The variance of a random variable is the expected value of the squared deviation from the mean of , :
    This definition encompasses random variables that are generated by processes that are … 展开

    Examples

    The exponential distribution with parameter λ is a continuous distribution whose probability density function is given by
    on the interval [0, ∞). Its mean can be shown to be
    Using … 展开

    Variance - Encyclopedia of Mathe…
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    https://zh.wikipedia.org/wiki/方差

    方差 - 维基百科，自由的百科全书

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    https://zh.wikipedia.org/zh-tw/方差

    變異數 - 維基百科，自由的百科全書 - zh.wikipedia.org

  3. Encyclopedia of Mathematics
    https://encyclopediaofmath.org/wiki/Variance

    Variance - Encyclopedia of Mathematics

  4. Wikipedia
    https://simple.wikipedia.org/wiki/Variance

    Variance - Simple English Wikipedia, the free encyclopedia

  5. Brilliant
    https://brilliant.org/wiki/variance-definition

    Variance | Brilliant Math & Science Wiki

    网页2 天之前 · Learn how to calculate and interpret variance, a statistic that measures deviation in a probability distribution. Find definitions, properties, examples, and standard deviation formula.

  6. 其他用户还问了以下问题
    What is variance in statistics?
    The variance can also be thought of as the covariance of a random variable with itself: The variance is also equivalent to the second cumulant of a probability distribution that generates . The variance is typically designated as , or sometimes as or , or symbolically as or simply (pronounced " sigma squared").

    Variance - Wikipedia

    en.wikipedia.org
    What is variance in probability theory?
    In probability theory and statistics, the variance is a way to measure how far a set of numbers is spread out. Variance describes how much a random variable differs from its expected value. The variance is defined as the average of the squares of the differences between the individual (observed) and the expected value.

    Variance - Simple English Wikipedia, the free encyclopedia

    simple.wikipedia.org
    Is variance a measure of the deviation of a random variable?
    The variance is not the only conceivable measure of the deviation of a random variable from its expectation. Other measures of the deviation, constructed on the same principle, e.g. $\Ex|X-\Ex X|$, $\Ex (X-\Ex X)^4$, etc., are also possible, as are measures of deviation based on quantiles (cf. Quantile ).

    Variance - Encyclopedia of Mathematics

    encyclopediaofmath.org
    What is variance 2?
    The (population) variance σ 2 is the average of the squared deviations from the mean or (x i - μ) 2 - the square of the value's distance from the distribution's mean. Because of the squaring the variance is not directly comparable with the mean and the data themselves. The square root of the variance is called the Standard Deviation σ.

    Statistics/Summary/Variance - Wikibooks

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  7. Wikipedia
    https://en.wikipedia.org/wiki/Analysis_…

    Analysis of variance - Wikipedia

    网页Analysis of variance (ANOVA) is a statistical method to compare means of different groups and partition the variance into components. Learn the history, classes, and examples of ANOVA from this Wikipedia article.

  8. Wikipedia
    https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance

    Algorithms for calculating variance - Wikipedia

  9. WikiHow
    https://www.wikihow.com/Calculate-V…

    3 Ways to Calculate Variance - wikiHow

    网页2024年9月3日 · What is variance? Variance is a measure of how spread out a data set is, and we calculate it by finding the average of each data point's squared difference from the mean. It's useful when creating statistical …

  10. wikibooks.org
    https://en.wikibooks.org/wiki/Statistics/Summary/Variance

    Statistics/Summary/Variance - Wikibooks