David is planning to order shirts from a brand supplier. The supplier provides the following discount scheme based on order quantity (see Table below). Davids purchasing price is $12 per shirt from this supplier if the order size is no more than 999 shirts (0% discount). David can sell it at $20 per shirt. Based on the historical data, David estimates that demand is 1,800 shirts. David also believes that if he orders more shirts, he can sell all left shirts (after meeting the demand) if he sells them at an on sales price of $9 per shirt.

Table: Discount scheme Shirts ordered Discount 1-999 0% 1,000-1,499 1.5% 1,500-1,999 3.0% 2,000-2,499 7.0% 2,500 and above 10.0%

Develop an Excel model to help David decide how many shirts should he order to maximize his profit? Please present the impact of order quantity on Davids profit and plot this impact. 3) How does on sales price affect Davids order quantity decision? If David thinks that he can charge an on sales price of $10 per shirt, what is the order quantity that can maximize Davids profit? What is the extra profit that David can earn?