The GH company uses a cost accounting system by process and presents the following information for the month of July 2017: Its products are electronic components, manufactured in series for which its Elaboration is paid for by work cards. 37,000 units were started, the Material requisitions were $ 83,000, conversion costs were $ 98,000 and 33,000 units were completed. Starting inventory as of July 1 was 8,500 units with a cost of $ 31,000 of raw material and $ 39,000 conversion costs (100% material advance premium and 80% conversion costs). The ending inventory is 12,500 units, which have 100% raw material and the 40% conversion costs. Based on previous information: a) Prepare the certificates of physical units, that of equivalent production and that of cost allocation. b) Evaluate with the three inventory valuation methods (FIFO, LIFO and CPP) and determine the unit cost of production