help me solve just D.

M Cotteloor Electronics supplies microcomputer circuitry to a company that incorporates microprocessors into refrigerators and other home appliances One of the components has an annual demand of 270 units, and this in constant throughout the year. Carrying cost is estimated to be $0.75 per unit per year, and the ordering (setup) cost is $21 per ordet a) To minimize cost. how many unts should be ordered each time an ceder la placed? 122.96 units (round your response to two decimal plocom D) How many orders per year are needed with the optimal policy 220 order (round your response to two decimal places). c) What is the average inventory it costs are minimized? 6146 units (round your response to two decimal places) d) Suppose that the ordering (setup) cost is not $21, and Cotter has been ordering 175 units each time an order is placed. For this order policy (of 175) to be optimal, the ordering (setup) cost would have to be fround your response to two decimal places)