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    n=49, sum of (x-200)=245, sum of ((x-200)^2)=9849

    Find the mean and standard deviation. Here's what I have so far.

    (sum of x-200)+(200*49)=245 +(200*49)
    sum of x= 10045
    mean of x=205.
    How on earth do I go about finding the standard deviation???
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    sqrt(9849/49 - (245/49)^2)

    The 200 simply codes the data but won't affect the standard deviation.
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    (Original post by sciortino)
    sqrt(9849/49 - (245/49)^2)

    The 200 simply codes the data but won't affect the standard deviation.
    oh okay, so instead of trying to find x itself, i just use (x-200) as my x and (x-200)^2 as my x^2, if you get what I mean??
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    Yes, because you want the standard deviation and the additive coding won't affect the answer.
    If you sought the mean you would need to decode by adding back the 200
 
 
 

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