Table 13-7 Teacher's Helper is a small company that has a subcontract to produce instructional materials for disabled children in publlc school districts. The ouner rents several small rooms m an office building in the suburbs for S600 a month and has leased computer equipment that costs S480 a month. Output (Instructional F ixed Modules per Month) Costs 1,080 1,080 Variable Costs 400 1,350 1,900 2500 4,100 7,300 Average Total Fixed Cost 1,480 2,430 216 4,280 10,880 Average Variable Average Marginal T otal