Table schema:
CREATE TABLE dorm (student_capacity INTEGER); CREATE TABLE student (age INTEGER, stuid VARCHAR); CREATE TABLE lives_in (stuid VARCHAR, dormid VARCHAR); CREATE TABLE dorm (dormid VARCHAR, student_capacity INTEGER)

Question: Find the average age of students who are living in the dorm with the largest capacity.
SQL: SELECT AVG(T1.age) FROM student AS T1 JOIN lives_in AS T2 ON T1.stuid = T2.stuid JOIN dorm AS T3 ON T3.dormid = T2.dormid WHERE T3.student_capacity = (SELECT MAX(student_capacity) FROM dorm)