E-R diagram

Draw the preliminary class diagram for the system described in the following requirements (the cardinality of the relationships is optional).

Question Two

Redraw the following class diagram into the equivalent E-R diagram.

Question Three

Convert the following E-R diagram, which represent a manufacturing system into relations. Make sure to specify all the primary keys.

 

Question Four

Identify all foreign keys in relations you identified in Question 3 and justify your decisions.