The discussion of abstraction in section 1.3.1 noted that one does not need to understand the makeup of the components as long as "everything about the detail is just fine." the case was made that when everything is not fine, one must be able to deconstruct the components, or be at the mercy of the abstractions. in the taxi example, suppose you did not understand the component, that is, you had no clue how to get to the airport. using the notion of abstraction, you simply tell the driver, "take me to the airport." explain when this is a productivity enhancer, and when it could result in very negative consequences.

Following is a list of various costs incurred in producing replacement automobile parts. with respect to the production and sale of these auto parts, classify each cost as either variable costs, fixed costs, or mixed costs. 1. oil used in manufacturing equipment 2. plastic 3. property taxes, $165,000 per year on factory building and equipment 4. salary of plant manager 5. cost of labor for hourly workers 6. packaging 7. factory cleaning costs, $6,000 per month 8. metal 9. rent on warehouse, $10,000 per month plus $25 per square foot of storage used 10. property insurance premiums, $3,600 per month plus $0.01 for each dollar of property over $1,200,000 11. straight-line depreciation on the production equipment 12. hourly wages of machine operators 13. electricity costs, $0.20 per kilowatt-hour 14. computer chip (purchased from a vendor) 15. pension cost, $1.00 per employee hour on the job

What are six resources for you decide which type of business to start and how to start it?

T-comm makes a variety of products. it is organized in two divisions, north and south. the managers for each division are paid, in part, based on the financial performance of their divisions. the south division normally sells to outside customers but, on occasion, also sells to the north division. when it does, corporate policy states that the price must be cost plus 20 percent to ensure a "fair" return to the selling division. south received an order from north for 300 units. south's planned output for the year had been 1,200 units before north's order. south's capacity is 1,500 units per year. the costs for producing those 1,200 units follow