Final answer:
The task involves calculating overhead rates and allocating costs using different methods, including plantwide, departmental, and activity-based costing, as well as understanding economies of scale and average fixed costs.
Step-by-step explanation:
The question requires the calculation of overhead rates and the allocation of them using a plantwide approach and a departmental approach. It also involves developing a segmented income statement using activity-based costing (ABC) and calculating the break-even point for a particular model. The key elements of this task include understanding how fixed costs (also known as overhead) and the quantity of output produced affects the average fixed cost, and how this concept translates into various costing methods. Additionally, understanding the economies of scale and how they affect the average cost of production is crucial in formulating a more accurate cost allocation structure that reflects actual use of company resources.