Figure 8.8b: Bivariate scatterplot for
data in Table 8.2
Pearson
correlatio
n r—8.11
which is computationally an easier formula to use with a pocket calculator.
Using the data in Table 8.4, for the variables MATHS and SMATHS, SSXY= 223.6,
SSYY (MATHS)=60.4 and SSXX (SMATHS)=1030.4. (These correspond with the values
calculated in the previous regression example). Using the general formula for calculating
sums of squares, for the two variables MATHS and RAVEN,
Statistical analysis for education and psychology researchers 286