Table : TABLE 15-3. Calculating the Numerator of the Correlation Coefficient
Absences (X)(X − MX)Exam Grade (Y)(Y − MY)(X − MX)(Y − MY)
4      0.6      82      6      3.6      
2      −1.4      98      22      −30.8      
2      −1.4      76      0      0.0      
3      −0.4      68      −8      3.2      
1      −2.4      84      8      −19.2      
0      −3.4      99      23      −78.2      
4      0.6      67      −9      −5.4      
8      4.6      58      −18      −82.8      
7      3.6      50      −26      −93.6      
3      −0.4      78      2      −0.8      
MX = 3.400             MY = 76.000             Σ[(X 2 MX)(Y 2 MY)] = −304.0