Answer:
The costs associated with the production are:
- For the 111st oven, it costs $114.07
- The 221st oven comes to $122.71
- The 311st oven amounts to $140.59
The marginal costs for x equal to 110, 220, and 310 are outlined as follows:



Step-by-step explanation:
The daily cost for manufacturing the microwave ovens can be expressed through the given function:

(a) To determine the actual cost of the 111st oven, subtract the total cost of producing the first 110 ovens from that of the first 111 ovens:
![C(111)-C(110)=[0.0002(111)^3 - 0.06(111)^2 + 120(111) + 5000]-[0.0002(110)^3 - 0.06(110)^2 + 120(110) + 5000]\\\\C(111)-C(110)=17854.27-17740.2\\\\C(111)-C(110)=114.07](https://tex.z-dn.net/?f=C%28111%29-C%28110%29%3D%5B0.0002%28111%29%5E3%20-%200.06%28111%29%5E2%20%2B%20120%28111%29%20%2B%205000%5D-%5B0.0002%28110%29%5E3%20-%200.06%28110%29%5E2%20%2B%20120%28110%29%20%2B%205000%5D%5C%5C%5C%5CC%28111%29-C%28110%29%3D17854.27-17740.2%5C%5C%5C%5CC%28111%29-C%28110%29%3D114.07)
For the 221st oven:
![C(221)-C(220)=[0.0002(221)^3 - 0.06(221)^2 + 120(221) + 5000]-[0.0002(220)^3 - 0.06(220)^2 + 120(220) + 5000]\\\\C(221)-C(220)=30748.31-30625.6\\\\C(221)-C(220)=122.71](https://tex.z-dn.net/?f=C%28221%29-C%28220%29%3D%5B0.0002%28221%29%5E3%20-%200.06%28221%29%5E2%20%2B%20120%28221%29%20%2B%205000%5D-%5B0.0002%28220%29%5E3%20-%200.06%28220%29%5E2%20%2B%20120%28220%29%20%2B%205000%5D%5C%5C%5C%5CC%28221%29-C%28220%29%3D30748.31-30625.6%5C%5C%5C%5CC%28221%29-C%28220%29%3D122.71)
For the 311st oven:
![C(311)-C(310)=[0.0002(311)^3 - 0.06(311)^2 + 120(311) + 5000]-[0.0002(310)^3 - 0.06(310)^2 + 120(310) + 5000]\\\\C(311)-C(310)=42532.79-42392.2\\\\C(311)-C(310)=140.59](https://tex.z-dn.net/?f=C%28311%29-C%28310%29%3D%5B0.0002%28311%29%5E3%20-%200.06%28311%29%5E2%20%2B%20120%28311%29%20%2B%205000%5D-%5B0.0002%28310%29%5E3%20-%200.06%28310%29%5E2%20%2B%20120%28310%29%20%2B%205000%5D%5C%5C%5C%5CC%28311%29-C%28310%29%3D42532.79-42392.2%5C%5C%5C%5CC%28311%29-C%28310%29%3D140.59)
(b) If C(x) represents the total cost function, then the marginal cost function is its derivative, expressed as C'(x).
We need to calculate the derivative of the total cost function:

The marginal costs when x equals 110, 220, and 310 are represented by


