Question: What is the name and the average gpa of department whose students have the highest average gpa?
SQL: SELECT T2.dept_name ,  avg(T1.stu_gpa) FROM student AS T1 JOIN department AS T2 ON T1.dept_code  =  T2.dept_code GROUP BY T1.dept_code ORDER BY avg(T1.stu_gpa) DESC LIMIT 1