note 8269 deleted from sort by jmoore

Is there anyone who can help me here? I have a 2D array: $student[x][y] for a list of student records. $student[x][0] is for student_name $student[x][1] is for subject name $student[x][2] is for score of that subject $student[0][y] is record number 1 $student[1][y] is record number 2 one student can have number of records (have number of subjects) Question 1 - who do I caculate average score of a particular subject? Question 2 -who do I display student marks in sorted order for each suject? Thanks