Table 13-13 teacher's helper is a small company that has a subcontract to produce instructional materials for disabled children in public school districts. the owner rents several small rooms in an office building in the suburbs for $600 a month and has leased computer equipment that costs $480 a month. output (instructional modules per month) fixed costs variable costs total cost average fixed cost average variable cost average total cost marginal cost 0 $1,080 1 $1,080 $ 400 $1,480 $400 2 $965 $450 3 $1,350 $2,430 4 $1,900 $475 5 $2,500 $216 6 $4,280 $700 7 $4,100 8 $5,400 $135 9 $7,300 10 $10,880 $980 refer to table 13-13. what is the marginal cost of creating the tenth instructional module in a given month