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Math Help - Probabilities of z-scores

  1. #1
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    Probabilities of z-scores

    Does anyone have a link to the chart that you use to find the probabilities of z-scores? Mine is not in my book.

    A question like:

    P(-2.02<z<0.58)

    How do you go about handling that?
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  2. #2
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    Quote Originally Posted by GoneFishing View Post
    Does anyone have a link to the chart that you use to find the probabilities of z-scores? Mine is not in my book.

    A question like:

    P(-2.02<z<0.58)

    How do you go about handling that?
    Firstly the chart does not work for all values.
    You need to simplify that.
    P(-2.02<z<.58)=P(-2.02<z<0)+P(0<z<.58)
    Now,
    P(0<z<.58) you can find by chart.
    And,
    P(-2.02<z<0)=P(0<z<2.02) because the normal curve is symetrrical. And then use the chart.
    Heri
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  3. #3
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    So when you get those decimals, do you add them together or subtract them to get the final answer?
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  4. #4
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    Quote Originally Posted by GoneFishing View Post
    So when you get those decimals, do you add them together or subtract them to get the final answer?
    Of course.
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  5. #5
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    Add or subtract? I'm struggling here. lol The concept of the greater than or less than sign is bothering me, too.

    If you have this:

    P (z.>2.18) and P (z<1.77)...what is the difference in the final answer?
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  6. #6
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    See here

    RonL
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