I am stuck dont know how to resolve part 3 and 4

Timing Technology, Inc, manufactures timing devices, During 20 times 1. 900,000 units were complete and transferred to finished-goods inventory, On December 31, 20 times 1 there were 300,000 units in work in process. These units were 50 percent complete as to conversion and 100 percent complete as to direct material. Finished-goods inventory consisted of 200,000 units. Materials are added to production at the beginning of the manufacturing process, and overhead is applied to each product at the rate 60 percent of direct labor cost. There was no finished-goods inventory on January 1, 20x 1. A review of the inventory cost records disclosed the following information: Prepare schedules as of December 31, 20x 1, to compute the following: Physical flow of units. Equivalent units of production using the weighted-average method. Costs of the December 31, 20x 1, finished-goods inventory and work-in-process inventory. Timing Technology, Inc, manufactures timing devices, During 20 times 1. 900,000 units were complete and transferred to finished-goods inventory, On December 31, 20 times 1 there were 300,000 units in work in process. These units were 50 percent complete as to conversion and 100 percent complete as to direct material. Finished-goods inventory consisted of 200,000 units. Materials are added to production at the beginning of the manufacturing process, and overhead is applied to each product at the rate 60 percent of direct labor cost. There was no finished-goods inventory on January 1, 20x 1. A review of the inventory cost records disclosed the following information: Prepare schedules as of December 31, 20x 1, to compute the following: Physical flow of units. Equivalent units of production using the weighted-average method. Costs of the December 31, 20x 1, finished-goods inventory and work-in-process inventory