I have two variables, let's say, Variable A and B. Variable A contains marks of all subjects and variable B contains marks of a specific subject. Number of student (sample) is 50. I have to calculate correlation between A and B using Pearson / Spearman depending on normality test.
What I have found?
Including value of B in A and excluding value of B from A shows different results.
For each student, since A value (total marks) contains value of B (specific subject marks), should I exclude B value from A for each of the student at the time of correlation coefficient calculation?