Company C is a refrigerator manufacturer. It needs 36,000 compressors every year to balance consumption. The annual production time is 36. 0 days, each order cost is 160 yuan, each compressor holding rate is 80 yuan, the purchase price of each compressor is 900 yuan. According to experience, it usually takes 5 days for the compressor to enter the usable state from the issue of orders, and the amount of insurance reserve is 200.

(1) Calculation of economic order volume.

(2) Calculate the best order times of the year.

(3) Calculate the minimum inventory cost.

(4) Calculate the reorder point.