Explore BrainMass

Explore BrainMass

    normal distribution question

    Not what you're looking for? Search our solutions OR ask your own Custom question.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    Problems 4.9, 4.12, 4.13, 4.20 from the attached tasks.

    © BrainMass Inc. brainmass.com March 4, 2021, 6:03 pm ad1c9bdddf
    https://brainmass.com/statistics/students-t-test/normal-distribution-question-25896

    Attachments

    Solution Preview

    See the attached files.
    4.9: this is a normal distribution question:
    Let's define: m=1000, S2 = 10000,
    then the standard deviation is SD=SQRT(S2)=100
    (a) by the formula: z = (X-m)/SD
    z1 = (1200-1000)/100 = 2
    from a z table, we find that Pr(z<2) = 0.9773

    z2 = (800-1000)/100 = -2
    Pr(z< -2) = 1- Pr(z<2) = 1-0.9773 = 0.0227

    then Pr(800<x<1200) = Pr(-2<z<2)= Pr(z<2) - Pr(z< -2) = 0.9773-0.0227 = 0.9546

    (b) As shown in (a), Pr(x>1200) = 1- Pr(x<1200) = 1- Pr(z<2) = 1-0.9773 = 0.0227
    (c) As shown in (a), Pr(x<800) = Pr(z< -2) = 1- Pr(z<2) = 1-0.9773 = 0.0227
    (d) z3 = (5000-1000)/100 =40
    Obviously, Pr(z>40) = 1 - ...

    Solution Summary

    A normal distribution question is emphasized.

    $2.49

    ADVERTISEMENT