Doofus Music Company manufactures air guitars and uses a WEIGHTED AVERAGE process costing system tocollect costs related to its production. Doofus only accounts for conversion costs because the only direct material, air, has no cost. The following information relates to September production: Percent complete with respect to conversion costs 20% Number of units 20,000 90,000 8,000 Work in process, September 1....... Units started into production ........ Work in process, September 30..... 75% Conversion cost in work in process on September 1.......... R 263,120 Conversion cost added to production during September... 5.262.400 Total cost..... R5,525,520 Calculate the amount of cost that Doofus should assign to the units (guitars) in work in process on September 30. (17)