13. A linear cost function is C(x)= 28.37x +5,580, where x represents the number of units produced. What is the cost
of producing one more item if 75 are currently being produced? Round your answer to the nearest cent.
a. $7,736.12
b. $28.37
c. $5,580.00
d. $5,608.37
e. $75.00