Pearson's r

This section introduces Pearson's correlation and explains what the typical values represent. It then elaborates on the properties of r, particularly that it is invariant under linear transformation. Finally, it introduces several formulas we can use to compute Pearson's correlation.

Computing Pearson's r

Answers


  1. Compute the correlation of the two variables. \mathrm{0.4686}

  2. The mean is \mathrm{5}. The deviation score is \mathrm{6-4=2}.

  3. Small letters refer to deviation scores. Multiply the deviation score for each \mathrm{x} value by the corresponding deviation score for each \mathrm{y} value. Then add these values together. \mathrm{(-2)(0) + (0)(-1) + (2)(1) = 2}

  4. The correlation will not change. Since the scores are converted to deviation scores, adding \mathrm{12} will have no effect.