Excel - Formula for taking avg with filters

Hi Experts,

I am new with excel and want to do the follwing.

1. I have sheet of all students with their names, subjects and grades
2. I have another list "Summary" where I want to calculate average of students based on their subjects. like; Subject 1: Avg = 3
3. All this I want is without using filters functionality of excel through mouse clicks.

I am more familiar with SQL so this is what I am looking for (in excel);

Aveg sub= Avg (select numbGrade from students where subject="SP")

This should give me an average grades of all students for a specific subject.

Appreciate your earlist help.

Thanks!