Find the id and city of the student address with the highest average monthly rental.
CREATE TABLE Student_Addresses (address_id VARCHAR); CREATE TABLE Addresses (city VARCHAR, address_id VARCHAR)
[SQL] SELECT T2.address_id, T1.city FROM Addresses AS T1 JOIN Student_Addresses AS T2 ON T1.address_id = T2.address_id GROUP BY T2.address_id ORDER BY AVG(monthly_rental) DESC LIMIT 1 [/SQL]