Answer:
Hello there! There are 4 parts to this question, all regarding relational database concepts.
Explanation:
Parts 1, 2, 3, 4 are drawn in attachments. For Part 4, the "foreign keys" would be the id fields of the joining table, and the "primary keys" are the IDs of the table itself. Data types are "integer" for ID, "string" for text columns like Name and Location, and "Decimal" for Hourly rate in the Timesheet table. Note that we can further simplify the erd from the one constructed earlier in part 3 to remove the Project Manager model and instead add a Project Manager "boolean" flag in the Employee table since a Project Manager is also an Employee.
