Explore BrainMass

Explore BrainMass

    Chi-Squared Problems

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

    1. For the following set of scores, find the value of ach expression:
    X
    6
    -1
    0
    -3
    -2

    a. ∑X
    b. ∑X²
    c. ∑(x+3)

    2. The following frequency distribution presents a set of exam scores for class of n=20 students.

    X
    6
    -1
    0
    -3
    -2
    X f cf c%
    90-99 4 20 100
    80-89 7 16 80
    70-79 4 9 45
    60-69 3 5 25
    50-59 2 2 10

    A. find the 30th percentile
    B. find the 88 percentile
    C. what is the percentile rank for x=77
    D. what is the percentile rank for x=90

    © BrainMass Inc. brainmass.com June 3, 2020, 8:00 pm ad1c9bdddf
    https://brainmass.com/statistics/percentile/chi-squared-problems-120571

    Attachments

    Solution Preview

    Please see the attached file.

    Qk = L+w/fk*(kn-cfb)
    Where
    Qk = the kth percentile
    L = lower limit of the class interval that includes the kth percentile
    n = total frequency
    cfb = ...

    Solution Summary

    Two problems are solved dealing with chi-squared distributions and percentile ranks.

    $2.19

    ADVERTISEMENT