Anatural monopoly, such as a local electricity provider, is the result of: i. a firm owning or controlling a key input used in the production process ii. economies of scale existing over a wide range of output iii. long-run average total costs declining continuously as output increases iv. long-run total costs declining continuously as output increases

Last year, western corporation had sales of $5 million, cost of goods sold of $3 million, operating expenses of $175,000 and depreciation of $125,000. the firm received $40,000 in dividend income and paid $200,000 in interest on loans. also, western sold stock during the year, receiving a $40,000 gain on stock owned 6 years, but losing $60,000 on stock owned 4 years. what is the firm's tax liability?

Email viruses are typically launched by people who modify header information to hide their identity. brightmail's enrique salem says that in the future, your email reader will authenticate the sender before putting hte message in your inbox. that way, you will know the source of all the emails you read. alan nugent of novell says, "i'm kind of a fan of eliminating anonymity if that is the price for security." will eliminating anonymity make computers more secure?

Employees at a library check out books to patrons. books have an isbn and a name. the library sometimes has multiple copies of the same book. books have one or more authors. a patron is an individual who has an active (non-expired) library card. for each library card, we store the person's first and last names and their address. for each employee, we store their employee id, current salary, first and last name and their address. we also store the employee id of their current manager. each time we check out a book to a patron we need to store the date of the transaction, the employee who checked out the book to the patron, and the library card of the patron. some employees have library cards. if an employee patron turns in a book late, the fine that they pay is a percentage of their salary. some employees are authors who have library cards—they are allowed to check out as many books as they like.