The model of aggregate demand and aggregate supply a. is a straightforward extension of the model of supply and demand for a particular market, in which substitution of resources between markets is highlighted. b. is different from the model of supply and demand for a particular market, in that we cannot focus on the substitution of resources between markets to explain aggregate relationships. c. is different from the model of supply and demand for a particular market, in that we have to separate real and nominal variables in the aggregate model. d. is a straightforward extension of the model of supply and demand for a particular market, in which the interaction between real and nominal variables is highlighted.

Which of the following best explains how the invention of money affected the barter system? a. the invention of money supplemented the barter system by providing a nonperishable medium of exchange b. the invention of money completely replaced the barter system with a free-market system c. the invention of money had no effect on the barter system d. the invention of money drastically reduced the value of goods used in the barter system 2b2t

For many years, kellogg's frosted flakes, a ready-to-eat breakfast cereal, was perceived as a cereal for children. tony the tiger, a cartoon character, extolled frosted flakes, and advertisements depicted children enjoying the product with tony in competitive situations. recently, in response to declining sales of frosted flakes, the cereal maker has adopted a new series of advertisements that show adults admitting that they enjoy frosted flakes, too. kellogg's is attempting to

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.