Answer:
The total cost of producing 91 units of ACME rocket fuel is $3999.99.
Step-by-step explanation:
The Marginal Cost is given by the following function

The total cost function is the integrative of the marginal cost function. So:



In which K, the integrative constant, is the fixed cost. So
.
1. Find the total cost of producing 91 units of ACME rocket fuel.
This is TC(91).
So

The total cost of producing 91 units of ACME rocket fuel is $3999.99.