Find the max, average, and minimum gpa of all students in each department.
SELECT max(stu_gpa) ,  avg(stu_gpa) ,  min(stu_gpa) ,  dept_code FROM student GROUP BY dept_code
max gpa = MAX(stu_gpa); average gpa = AVG(stu_gpa); minimum gpa = MIN(stu_gpa); each department refers to GROUP BY dept_code;