4 - A local bicycle store operates 365 days a year. The monthly holding cost for the bicycle is S10. The dealer sells an average of 30 bikes per week. If the dealer does not have a bike when a customer orders, then the bike becomes backordered. The shortage cost per unit of backordered is estimated to be $3 per week. The ordering cost for each order is $80. Determine the following: The optimum order quantity Maximum inventory level The portion of time customers have to wait for backordered bicycle Total cost b. c. d