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Getting Weighted Std Dev for probability.. - Texas Instruments BA-II Plus Calculator

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Sorry, boss.

But getting standard deviation from a probability distribution would probably be best done by hand (of course, with the use of a computational device for those hard-to-reach fractions).

If your distribution question has a long line of events (IE, data points) then you'd probably want to use a more advanced calculator.

Nevertheless....I will return this afternoon with a more informed answer after I tinker with my BA-II Plus.

Whenever I do these, though, I usually pop open my TI89 Titanium (or of course just do it by hand).


Posted on Mar 12, 2011

  • Math Cheetah Mar 13, 2011

    MO MO....


    I just finished messing around with the good old BA II Plus and this is what I've found:

    You CAN find an unweighted mean & standard deviation.

    You CANNOT find a weighted standard deviation.

    SORRY; judging by your question it seems as if you may have already come to this conclusion. The statistics menu on the BA II Plus just doesn't go into detail for a random variable like that.

    However, you CAN use a TI Graphing Calculator to set up a few lists which will aide in discovering the standard deviation of a discrete random variable.




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