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Math Help - The normal distribution

  1. #1
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    The normal distribution

    3. Using the standard normal distribution table, find the probability values of the following:

    P(z < 1.8)
    P( z > 1.8)
    P(> -2.37)
    P(1.76 < Z > 2.57)

    any idea how to start this
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  2. #2
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    is there a tutorial i can get
    with formulas and stuff without using jus the calculator
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    Nope, this is just an exercise of reading values from a table or using technology to get the values.

    If you have it just use excel


    P(z < 1.8)

    Code:
    =normsdist(1.8)

    P( z > 1.8)

    Code:
    =1-normsdist(1.8)

    P(> -2.37)

    Code:
    =1-normsdist(-2.37)

    P(1.76 < Z > 2.57) do you mean P(1.76 < Z < 2.57) ? if so

    Code:
    =normsdist(2.57)-normsdist(1.76)
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  5. #5
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    =normsdist(1.8)
    got 0.4641 on the table

    now what to do from there
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  6. #6
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    also got to do a sketch
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  7. #7
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    Quote Originally Posted by math321 View Post
    =normsdist(1.8)
    got 0.4641 on the table
    P(Z<1.8) = 0.9641

    You found P(0<Z<1.8) = 0.4641
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  8. #8
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    so i have to add .5
    is dat it
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  9. #9
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    and for this 1 P( z > 1.8)
    will it be .5 - .4691
    or 1 - .4691
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  10. #10
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    Quote Originally Posted by math321 View Post
    so i have to add .5
    is dat it
    Well that will get you the answer, but do you understand the process?
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  11. #11
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    yep slightly better
    and for this 1 P( z > 1.8)
    will it be .5 - .4691
    or 1 - .4691
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  12. #12
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    Quote Originally Posted by math321 View Post
    yep slightly better
    and for this 1 P( z > 1.8)
    will it be .5 - .4691
    or 1 - .4691
    It will be neither of those.

    P(Z>1.8) = 1-0.9641

    You need to remember that P(Z<1.8)+P(X>1.8) = 1
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  13. #13
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    can u give me an idea of how the graph will look please
    starting to understand a little more
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  14. #14
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  15. #15
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    for this 1 P(> -2.37)

    i got 1 - 0.0089 = .9911
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