Assignment #4: Data Modeling and the Entity Relationship Model Purpose: To demonstrate the ability to understand the purpose and role of a data model and construct ERDs that represent relationships, minimum, and maximum cardinality using Crows foot modeling techniques. Instructions: NHD Development Group Inc wants to extend its database applications beyond the recording of dealers and sales. The company still wants to maintain data on dealers, booths, and sales, but it wants to include other data as well. Specifically, NHD wants to track customers (e.g., LName, FName, Address, City, State, Zip, Phone, Email) and what purchases they make. In addition, NHD has started to offer various types of short MSOffice courses and the mall management wants to be able to determine who has obtained training on which MSOffice application. With regard to dealers, the NHD management has determined that the dealers can be described with various subtype descriptions. Thus, a particular dealer might have a subtype description such as corporation, sole-proprietor, or partnership. For better management of the dealers, subtypes should be considered. Meaning that the DEALER table will be redesigned using subtypes. Using the NHD Development Group Inc. case, complete the following items: A. Draw an ER data model for the NHD Develoopment Group Inc. database schema after making the necessary revisions from previous work. Use the IE Crows Foot ER model for your ER diagrams. Justify the decisions you make regarding minimum and maximum cardinality. (Note: This can be done with bullet points.) *Note: This diagram should represent the original database schema only. B. Extend and modify the ER data model to meet NHDs new requirements. Use the IE Crows Foot ER model for your ER diagrams. Create appropriate idenitfiers and attributes for each entity. Justify the decisions you make regarding minimum and maximum cardinality. (Note: This can be done with bullet points.) *Note: This diagram should add the new entities that would address the new requirements described above (e.g., the customer, course offerings and dealer subtypes). C. Describe how you would go about validating the model in part B. Save each data model with a unique filename and convert each to an image file. Create one single document by identifying each solution and placing the corresponding ERD in the proper section along with justifications. Convert the document as a pdf file, save, and submit.