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Math Help - Help Calculating Skewed Deviation Skewness

  1. #1
    Member cmf0106's Avatar
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    Help Calculating Skewed Deviation Skewness


    You may recall the formula for calculating skewed deviation skewness

    [OPTIONAL READING]ill get the sum of the deviation^3 and divide through by ns^3. So the sum of the deviations cubed is 5,286,216,555
    divide through by NS in this case 6 * 4263.17^3 = 4.648889288 e 11
    5,286,216,555/ 4.648889288 e 11 = cubed skewness of 6.826398755 e 19 which is unfortunately the same incorrect answer I arrived at before.

    [PROBLEM] Just to clarify here 5,286,216,555/6 * 4263.17^3 is all that needs to be solved for however 6.826398755 e 19 is not the correct answer and that's what my ti-83 keeps on giving me.

    Here was my instructors reply

    Your ns^3 is incorrect. Make sure you do s^3 first then multiply that by n (6); if in Excel it is easy to screw this up. I worked it through and got a very reasonable answer.

    Good luck,


    Could some one please tell me what the correct answer is, and what I did wrong so I can correctly solve it? Thanks!
    Last edited by cmf0106; September 25th 2008 at 04:47 PM.
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  2. #2
    Member cmf0106's Avatar
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    Just to clarify here 5,286,216,555/6 * 4263.17^3 is all that needs to be solved for however 6.826398755 e 19 is not the correct answer and that's what my ti-83 keeps on giving me.
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  3. #3
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    Quote Originally Posted by cmf0106 View Post
    Just to clarify here 5,286,216,555/6 * 4263.17^3 is all that needs to be solved for however 6.826398755 e 19 is not the correct answer and that's what my ti-83 keeps on giving me.
    Just to save the wheel being re-invented, the following is an excerpt of an exchange of pm's between myself and the OP:

    Originally Posted by cmf0106
    5,286,216,555 / 6 * 4263.17^3

    Everything up to this point is correct so all that needs to be solved is the above, thus some how everytime I am doing it wrong at this step.

    6.826398755 e 19 is incorrect that’s what I get when I attempt it
    Is it meant to be

    5,286,216,555 / (6 * 4263.17^3)

    or

    (5,286,216,555 / 6) * 4263.17^3?

    Your calculator will treat 5,286,216,555 / 6 * 4263.17^3 as the latter, not the former.

    Use brackets when using your calculator.

    meant to be
    So im guessing the parenthesis are not needed, im just using a ti-83 and put it in as "5,286,216,555 / 6 * 4263.17^3" .
    Either everyting up to that point is NOT correct, or you're making a data entry error with your calculator.

    ----------------------------------------------------------------------------------------------------------------------

    Is s = 4263.17? If so, you need the brackets like I said.
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  4. #4
    Member cmf0106's Avatar
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    Should I just put the brackets at the beginning and end at the expression then? IE [5,286,216,555 / 6 * 4263.17^3 ]
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  5. #5
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    Quote Originally Posted by cmf0106 View Post
    Should I just put the brackets at the beginning and end at the expression then? IE [5,286,216,555 / 6 * 4263.17^3 ]
    *Ahem*
    Quote Originally Posted by mr fantastic View Post
    Just to save the wheel being re-invented, the following is an excerpt of an exchange of pm's between myself and the OP:



    Is it meant to be

    5,286,216,555 / (6 * 4263.17^3)

    or

    (5,286,216,555 / 6) * 4263.17^3?

    Your calculator will treat 5,286,216,555 / 6 * 4263.17^3 as the latter, not the former.

    [snip]

    Is s = 4263.17? If so, you need the brackets like I said.
    Read the red. Do the red.
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