Tuesday, June 23, 2009

practice problems for homework 1

1. Find the frequencies and relative frequencies for the ethnicity variable. Round the relative frequencies by the +/- 0.1% rule.

2. Using just the men's heights, find the following statistics from the sample. Round non-integer answers to the nearest tenth.

n =
x-bar =
mode =
median =
maximum value =
minimum value =
mid-range =

Answer in the comments.
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2 comments:

  1. AnonymousJune 23, 2009 at 11:16 PM

    I did this problem using only the height of the men in our class. Although there are 20 male students, only 18 put down a height, so n=18.
    x-bar=70.1
    mode=71
    Median=70
    maximum value=78
    minimum value=63
    mid-rang=70.5

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  2. Prof. HubbardJune 24, 2009 at 5:43 AM

    First answers incorrect in the second part. Thanks to the poster for catching the mistakes. Here are the correct answers.

    1.
    Frequencies

    f(African) = 2
    f(AfroAm) = 7
    f(Asian) = 12
    f(AsianAm) = 4
    f(EuroAm) = 3
    f(European) = 1
    f(Hispanic) = 5
    f(Other) = 4

    Relative frequencies

    p-hat(African) = 5.3%
    p-hat(AfroAm) = 18.4%
    p-hat(Asian) = 31.6%
    p-hat(AsianAm) = 10.5%
    p-hat(EuroAm) = 7.9%
    p-hat(European) = 2.6%
    p-hat(Hispanic) = 13.2%
    p-hat(Other) = 10.5%

    2. Men's heights put in order

    78 77 76 72 72 71 71 71 70 70 69 69 68 68 66 66 65 63


    n = 18
    x-bar = 70.1
    mode = 71
    median = 70
    maximum value = 78
    minimum value = 63
    mid-range = 70.5

    ReplyDelete