For this exercise you are to create an Entity-Relationship model. Our text touches on ERDs only very briefly in section 12.6 but this is an extremely important and useful concept. I am supplying several statements below. Your task is to create a simple ERD showing the relationship of the Entities to one another. Attributes are not in our scope - only entities. Be sure to name or Label each relationship. Review Figures 12.10, 12.11, and 12.12 (page 375 - https://pdfs.semanticscholar.org/d73f/72483b4fb30723629fb913ab949736956799.pdf). Notice the 1, m, and ns. These are called Cardinalities. In Figure 12.10 the model shows us that an Author can write 1 or more Novels. Create a simple ERD based on the following statements:

A Student can register for 1 or many Courses.

A Professor can teach 1 or many Courses

A Course is taught in 1 and only 1 Classroom

A Course may have 1 or more PreRequisites (this one is a bit tricky - check Figure 12:12 for a hint).