Bill's Bells Is a Company That Sells Several Kinds of Bells

Bill's Bells is a company that sells several kinds of bells to customers. Offered are cow bells, sleigh bells, dinner bells, bicycle bells, etc. Each bell style comes in various sizes. Bill is the chief purchasing agent for Bill's Bells, but there are several other purchasing agents as well. Bill prefers certain vendors for different bells; for instance he likes to buy cow bells from Bessie's Wholesale Bells. However, he sometimes purchases cow bells from Farm-time Follies. He has one preferred vendor and at least one back-up vendor for each type of bell. A vendor can be the preferred vendor for more than one kind of bell. Bill pays for all purchases made from a vendor during a given month on the last day of that month. Bill has several salespeople who are paid on commission. If a customer's assigned salesperson is not working when the customer comes in, another salesperson may assist that customer. The resulting commission would be split between the two salespeople. No sale is allowed without the customer paying at least 25% down at the time of the sale. Most customers pay the 25%, then make 3 more equal monthly installments. Some customers pay in full at the time of the sale. Cashiers process all cash receipts and cash disbursements. Bill's Bells has several different types of cash accounts into which cash receipts are deposited.
Required: Prepare business process level REA models with entities and relationships only to represent Bill's Bells acquisition/payment and sales/collection processes.