Partitioning Sums of Squares

To compute a deviation score you subtract the mean. 15 - 10 = 5.

To compute SSY, first compute the deviation scores by subtracting the mean (10) from each number. Then square these values and add them together: (-8)² + (-1)² + 1² + 3² + 5² = 100

SSY = SSY' + SSE; SSE = SSY - SSY' = 25.5 - 18.3 = 7.2

Proportion of variation explained = SSY'/SSY, so as SSY' increases, so does the proportion of variation explained.

Proportion explained = SSY'/SSY; SSY' = (.3)(20) = 6

r² is the proportion of variation explained. (.84)² = .71