For the following questions, applicable formulas are all required including the detail (No EXCEL worksheet, please). You need to list and explain all the parameters used with the values you determined (Make sure be consistent with the textbook). At the end of each problem, please make a statement to describe the process of the production plan (or order plan).

1. Nick's Camera Shop carries Zodiac instant print film. The film normally costs Nick $3.50 per roll, and he sells it for $5.50. Just assume Zodiac film has no shelf life. Nick's average sales are 21 rolls per week. His annual inventory holding cost rate is 25% and it costs Nick $20 to place an order with Zodiac. If Zodiac offers a 7% discount on orders of 400 rolls or more, a 10% discount for 900 rolls or more, and a 18% discount for 2000 rolls or more, determine Nick's optimal order quantity. Suppose The shop opens 280 days annually.