Task: Text to Code
Input (English): Step 1: find the average charge_amount in Charges table.
Step 2: For each row in Charges table, find the corresponding rows in Professionals table.
Step 3: find first_name, last_name in the results of step 2 whose charge_amount less than the results of step 1
Output (English): SELECT T2.first_name , T2.last_name FROM Charges AS T1 JOIN Professionals AS T2 WHERE T1.charge_amount < ( SELECT Avg ( T1.charge_amount ) FROM Charges AS T1 )