Write queries to solve the following problems. You will be using the Faculty-Assignment 3 database for this assignment. The code for the database content is attached. Review the procedures for creating and populating a database if necessary.

6. Select from the Course table the course reference number (Ref_Number), total revenue (Tot_Rev) and the average cost per student for the course in a column called Average Cost (Hint: divide the total revenue by the enrollment for each class to obtain the average per student).

7. Select the reference numbers and total revenues for the 5 highest total revenues for all courses, ordered from highest to lowest.

8. Select the reference numbers and enrollments of all courses that have a reference number that begins with 9.