- 2 - Suppose the fixed cost to make strawberry tarts is $250 and the marginal cost to make one tart is $0.35 . Write a formula for the average cost function. 0.35 Fixed Cost (K ) = $ 250 Margins ) rust as ( = F ( 9) $ 0:35 de 29 - 0.35 As the number of tarts produced gets increasingly large, what does the average cost per tart approach