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Homework Help: Finding Coefficient of Determination

  1. Apr 23, 2017 #1
    1. The problem statement, all variables and given/known data

    If the slope of the regression line is negative and the correlation coefficient is -0.5, coefficient of determination is:

    2. Relevant equations

    coefficient of determination: r2 = 1 - SSE/SST

    correlation coefficient: r = Sxy / (√Sxx * √Syy )

    3. The attempt at a solution
    r = -0.5
    r2 = 0.25 but because slope of regression line is negative, then coefficient of determination would be also negative.
    r2 = -0.25

    I am not sure if my though process in determining the correct answer is right or not.

    Attached Files:

  2. jcsd
  3. Apr 24, 2017 #2

    I like Serena

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    Homework Helper

    Hi Tchao,

    Indeed, the coefficient of determination is ##r^2=0.25##.
    And it is positive, since a square is always positive.
    It means that the coefficient of determination doesn't tell us whether the slope is upward or downward, only that there is a correlation.
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