The four entities in my diagram are the customer, invoice, company, and the product. in the customer entity there are customer key, first name, last name, street, city, state, zip, and phone number.These all relate to the customer so they are the attributes to the customer. In invoice is connected to the three entities so it is the primary key in the relationship. The product as attributes as well and they are Product key, name, price, quantity and vendor. The Company would attributes as well such as, company name, company ID, and that would be connected to the invoice number of the product.