Formulate SQL queries for the following:
(i) For each salesperson, list the salesperson's Employee_ID, Name, supervisor's Employee_ID, and supervisor's name.
(ii) For each product list the Product_code, stock_level, and the total quantity ordered.
(iii) For each Order list the Order_number, order date, Employee_ID of salesperson, total amount for products, and total amount for installation. The total amount for products is the sum of the unit price times quantity of the products ordered
