2. The Student-Club-School figure included with this homework assignment represents a situation of students who attend and work in schools and who also belong to certain clubs that are located in different schools. Study this diagram carefully to try to discern what business rules are represented. a. You will notice that cardinalities are not included on the Works For relationship. State a business rule for this relationship and then represent this rule with the cardinalities that match your rule. State the cardinality similarly to: "For every one student, there can be many courses; for every one course, there can be many students. Therefore, it is a m:n relationship. That is just an example. b. State a business rule that would make the Located In relationship redundant (i.e., where the school in which a club is located can be surmised or derived in some way from other relationships). c. Suppose a student could work only for a school that student attends but the student might not work at all. Would the Works For relationship still be necessary, or could you represent whether a student works for the school she attends in some other way (if so, how)? Draw ER Diagrams for each of the following situations. If you believe that you need to make additional assumptions, clearly state them for each situation. 3. A company has a number of employees. The attributes of EMPLOYEE include Employee ID (identifier), Name, Address, and Birthdate. The company also has several projects. Attributes of PROJECT include Project DI (identifier), Project Name, and Start Date. Each employee may be assigned to one or more projects, or may not be assigned to a project. A project must have at least one employee assigned and may have any number of employees assigned. An employee's billing rate may vary by project, and the company wishes to record the applicable billing rate (Billing Rate) for each employee when assigned to a particular project. If you have any associative entities on your ERD, be sure to explicitly show the primary key for? If so, what are the identifiers for those associative entities? Does your ERD allow a project to be created before it has any employees assigned to it? Explain. How would you change your ERD if the Billing Rate could change in the middle of a project?