Table : TABLE 15-4. Calculating the Denominator of the Correlation Coefficient
Absences (X)(X − MX)(X − MX)2Exam Grade (Y)(Y − MY)(Y − MY)2
4      0.6      0.36      82      6      36      
2      −1.4      1.96      98      22      484      
2      −1.4      1.96      76      0      0      
3      −0.4      0.16      68      −8      64      
1      −2.4      5.76      84      8      64      
0      −3.4      11.56      99      23      529      
4      0.6      0.36      67      −9      81      
8      4.6      21.16      58      −18      324      
7      3.6      12.96      50      −26      676      
3      −0.4      0.16      78      2      4      
   ∑ (X − MX)2 = 56.4                  ∑ (Y − MY)2 = 2262