CREATE TABLE student (stuid NUMBER, lname CLOB, fname CLOB, age NUMBER, sex CLOB, major NUMBER, advisor NUMBER, city_code CLOB)
CREATE TABLE minor_in (stuid NUMBER, dno NUMBER)
CREATE TABLE course (cid CLOB, cname CLOB, credits NUMBER, instructor NUMBER, days CLOB, hours CLOB, dno NUMBER)
CREATE TABLE enrolled_in (stuid NUMBER, cid CLOB, grade CLOB)
CREATE TABLE faculty (facid NUMBER, lname CLOB, fname CLOB, rank CLOB, sex CLOB, phone NUMBER, room CLOB, building CLOB)
CREATE TABLE member_of (facid NUMBER, dno NUMBER, appt_type CLOB)
CREATE TABLE department (dno NUMBER, division CLOB, dname CLOB, room CLOB, building CLOB, dphone NUMBER)
CREATE TABLE gradeconversion (lettergrade CLOB, gradepoint NUMBER)

Find the average grade point of student whose last name is Smith.
SELECT AVG(T2.gradepoint) FROM enrolled_in AS T1 JOIN gradeconversion AS T2 JOIN student AS T3 ON T1.grade = T2.lettergrade AND T1.stuid = T3.stuid WHERE T3.lname = "Smith"
SELECT AVG("T2"."gradepoint") FROM "enrolled_in" "T1" JOIN "gradeconversion" "T2" ON "T1"."grade" = "T2"."lettergrade" JOIN "student" "T3" ON "Smith" = "T3"."lname" AND "T1"."stuid" = "T3"."stuid"