CREATE TABLE customer (acc_type VARCHAR, acc_bal INT, credit_score INT)

For each account type, find the average account balance of customers with credit score lower than 50.
SELECT AVG(acc_bal), acc_type FROM customer WHERE credit_score < 50 GROUP BY acc_type
SELECT AVG("acc_bal"), "acc_type" FROM "customer" WHERE "credit_score" < 50 GROUP BY "acc_type"