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Math Help - Statistics variance

  1. #1
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    Statistics variance

    Im having trouble on exactly what variance is, and how to find it.

    Small bowl Large Bowl These are cereal bowls, and amount of
    mean=1.5 Mean=2.5 cearel they hold.
    SD =.3 SD = .4

    Expected value= 2.5-1.5= 1

    Whats the SD of the difference?
    Can someone explain this?
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  2. #2
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    Quote Originally Posted by Morgan82 View Post
    Im having trouble on exactly what variance is, and how to find it.

    Small bowl Large Bowl These are cereal bowls, and amount of
    mean=1.5 Mean=2.5 cearel they hold.
    SD =.3 SD = .4

    Expected value= 2.5-1.5= 1

    Whats the SD of the difference?
    Can someone explain this?
    The variance of the difference is the sum of the variances, which are the squares of the standard deviations.

    The SD of the difference is the square root of this variance.

    RonL
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