please make sure answer is correct. Optimal order quantity and total cost please

M. P. VanOyen Manufacturing has gone out on bid for a regulator component. Expected demand is 725 units per month. The item can be purchased from either Allen Manufacturing or Baker Manufacturing. Their price lists are shown in the table. Ordering cost is $55, and annual holding cost per unit is $4. Allen Mfg. Quantity Unit Price 1-499 $16.00 500-999 15.50 1000+ 15.00 Baker Mfg. Quantity Unit Price 1-399 $16.10 400-799 15.60 800+ 15.10 a) What is the economic order quantity if price is not a consideration? 489 units (round your response to the nearest whole number). b) Which supplier, based on all options with regard to discounts, should be used? Allen Mfg. c) What is the optimal order quantity and total annual cost of ordering, purchasing, and holding the component? The optimal order quantity is with a total cost of $ (round your responses to the nearest whole number)