I need help creating a physical DFD based on the information below? Can you provide me step by step in the way you did it because I am confused about it.

Prepare a physical DFD based on the output from Short Problem 4-1. REF PRB: a. Prepare a table of entities and activities for the Cornick, Inc. process described below. Cornick, Inc. Cornick, Inc. sells office products to businesses in the eastern region of the United States. Each month, the IT division at Cornick prints monthly statements and sends them to the accounts receivable (AR) department, where a clerk e-mails them to the customers. Cornick's customers mail their payments back to Cornick, where a clerk in AR batches the checks and sends them to the cashier. The AR clerk then uses the payment stub to enter the payments into the computer, where the AR master data are updated to record the payment. b. Using Microsoft Visio or other diagraming software, construct a context diagram based on the table you prepared in part (a)