Exam 1

  1. Metainformation

    Tag Value
    fileDescriptive-statistics_vufgb-variance-008-en_vufgb-variance-008-en
    namevufgb-variance-008-en
    sectionDescriptive statistics/Summary Statistics/Measures of Spread/Variance
    typeschoice
    solutionFALSE, FALSE, FALSE, TRUE
    TypeCalculation
    Program
    LanguageEnglish
    LevelStatistical Thinking

    Question

    Given is the sample below, consisting of 5 subjects with scores on a variable. What is the corresponding variance of the scores?


    1. FALSE: 2.42
    2. FALSE: 2.70
    3. FALSE: 5.84
    4. TRUE: 7.30

    Solution

    First, calculate the average: (6+3+8+4+1)5=225=4.4\frac{(6+3+8+4+1)}{5} = \frac{22}{5} = 4.4

    Next, calculate the variance (note that this is the standard deviation squared!): ((6−4.4)2+(3−4.4)2+(8−4.4)2+4−4.4)2+(1−4.4)2)(5−1)=(2.56+1.96+12.96+0.16+11.56)(5−1)=29.24=7.3\frac{((6-4.4)^2+(3-4.4)^2+(8-4.4)^2+4-4.4)^2+(1-4.4)^2)}{(5-1)} = \frac{(2.56+1.96+12.96+0.16+11.56)}{(5-1)} = \frac{29.2}{4} = 7.3


    1. Incorrect
    2. Incorrect
    3. Incorrect
    4. Correct