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    - Which one is an unbiased estimator for the population variance:
    (Sh^2 – [(Sh)^2]/n) / n - 1
    [S(x – mean)^2] / n - 1
    n / n – 1
    1 / n – 1 (Sx^2 – [(Sx)^2] / n)

    (where s is the sign for sum of)

    - On a graphical calculator, is standard deviation xon or xon^-1

    Also, can I check that you do need to learn these for S1 but I seem to have a tendency of learning things that aren’t even on the syllabus
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    (Original post by alison_141288)
    -

    - On a graphical calculator, is standard deviation xon or xon^-1

    Also, can I check that you do need to learn these for S1 but I seem to have a tendency of learning things that aren’t even on the syllabus
    standard deviation is xon^-1

    which exam board are you with?
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    aqa

    is sd =xon where you are using an unbiased estimator of the s.d. becuase im sure my teacher said that you sometimes had to use xon
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    hmm...anyone else know?
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    anyone?
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    For Edexcel they generally use s.d = xon

    Even in questions where this isn't entirely correct (where you should use xon-1), they still accept this.
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    how about for aqa though. is the general rule that you should e xon?
 
 
 
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