Respuesta :

C ( x ) = 15,000 + 70 x + 1,000 / x
C ` ( x ) = 70 - 1,000 / x² ;  x = 100
C ` ( 100 ) = 70 - 1,000 / 10,000 = 70 - 0.1 = 69.9
Answer:
The marginal costs at given production level are $69.9.