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    HELP! Stats Problemo....

    Hey there people

    Helping my nephew with a question he was set....He is given no data just the average and the questions asks him work out the standard deviation from that.

    How is that possible as I remember you needed all the data from where youy worked out the average and then work out standard deviation!?

    Any Idea...

    5 Comments

    do you have the numbers that make up that average or the sample size?

    You can't work out standard deviation from just the average. SD is a measure of how far the items deviate from the average, so using the average alone as a measurement can never give anything but 0 - one number can't deviate from itself.

    Original Poster

    Hi there

    I square rooted the average given and got the answer :thumbsup:

    Wooooo

    Thanks for you replies anyway!

    the question they gave you must have been wrong, should have said variance rather than average

    SkippyDoo;1721012

    Hi thereI square rooted the average given and got the answer … Hi thereI square rooted the average given and got the answer :thumbsup:WoooooThanks for you replies anyway!


    you can't square root an average.
    What you had was an average of the sum of each of the deviations squared.
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