issac 發問於 科學及數學數學 · 1 十年 前

數學問題一問,thx

show that:

Var(x)=[1/(n+1)]*sum of (x^2) - [n/(n-1)]*X^2 (X is mean)

1 個解答

評分
  • ?
    Lv 6
    1 十年 前
    最佳解答

    First, you have a typo in your question, the correct question should be:

    Var(x)=[1/(n-1)]*sum of (x^2) - [n/(n-1)]*X^2 (X is mean)

    Notice the minus sign above, here below is the proof:

    圖片參考:http://i187.photobucket.com/albums/x22/cshung/7007...

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