CHAPTER 21. A simplifying assumptiona.affects the important conclusions of an economic model.b.increases the level of detail in an economic model.c.limits the validity of an economic model’s conclusion.d.eliminates unnecessary details from an economic model.2. The ultimate purpose of an economic model is toa.explain reality as completely as possible.b.establish assumptions that closely resemble reality.c.help us to understand economic behavior.d.guide government policy decisions.3. An economic modeles equations to understand normative economic phenomena.b.often omits crucial elements.c.simplifies reality in order to focus on crucial elements.d.cannot be proven wrong.4. Which of the following activities would occur in a market for factors of production?a.Reesa buys a new computer to help balance her personal checkbook.b.Randy pays a speeding ticket.c.Ian mows his grass.d.General Motors hires additional workers to run a third-shift at a factory.5. Which of the following activities would occur in a market for goods and services?a.Harry mows his grass.b.General Motors hires additional workers to run a third shift at a factory.c.Jane bakes pies for Thanksgiving dinner.d.Dolly buys a ticket to a ball game.6. The three sources of income for the household area.taxes, subsidies from the government, and rent.b.wages, rent, and profit.c.wages, rent, and subsidies from the government.d.wages, rebates, and rent.7. Households play what role(s) in the circular flow diagram?a.purchasers of factors of production and sellers of services.b.purchasers of factors of production and sellers of goods.c.purchasers of goods and services only.d.purchasers of goods and services and sellers of factors of production.8. Which of the following is not an assumption that underlies an economy’s productio n possibilities frontier?a.fixed income.b.fixed resources.c.unchanged technology.d.fully employed resources.9. Which of the following would not result in an outward shift of a nation’s production possibilities frontier?a. a reduction in the unemployment rate.b. a rise in labor productivity.c.advances in technology.d.an expanding resource base.10. The production possibilities frontier demonstrates the basic economic principle thata.economies are always efficient.b.assuming full employment, supply will always determine demand.c.assuming full employment, an economy is efficient only when the productionof capital goods in a particular year is greater than the production ofconsumption goods in that year.d.assuming full employment, to produce more of any one thing, the economymust produce less of at least one other good.11. Suppose an economy has the production possibilities frontier shown in the diagram and is operating at position A. Which of the statements below is false?a.This economy could produce more of both capital and consumption goods.b.This economy is experiencing full employment.c.This economy could produce more capital goods without decreasing thequantity of consumption goods produced.d.This economy could produce more consumption goods without decreasing thequantity of capital goods produced.OBJECTIVE: 3 RANDOM: Y12. Opportunity costs most often increase as you move down a production possibilities frontier becausea.resources are not completely adaptable to alternative uses.b.factors of production are limited and human wants are unlimited.c.efficiencies are generated by large-scale production.d.economic efficiency is only possible in the short run.13. All points on a production possibilities frontier show thea.maximum satisfaction that households receive from their purchases of goods.b.minimum quantities of resources that must be used to produce a givenquantity of output.c.maximum output that society can produce with given resources andtechnology.d.minimum output that society can produce with given resources andtechnology.14. The branch of economics that is concerned with the overall performance of the economy is calleda.resource economics.b.contemporary economics.c.macroeconomics.d.microeconomics.15. Which of the following questions would not be of particular interest to a microeconomist?a.Why do national economies grow?b.What percentage of consumer income is spent on entertainment?c.Why do workers refer the 4-day workweek?d.What happens to worker productivity when the job shifts to a 4-day workweek?16. The television network newscaster reports that the national inflation rate in the past year equaled 4 percent. This report is most likely prepared from work done by a(n)a.microeconomist.b.normative economist.c.macroeconomist.d.social scientist rather than an economist.17. The Secretary of Labor states that wage rates in the country have risen by 2 percent this past year. The head of a local labor union states that wage gains should have been higher. The Secretary’s statement is a _________________ economic stateme nt, and the labor head’s statement is a __________________economic statement.a.normative; normativeb.normative; positivec.positive; normatived.positive; positive18. “An increase in interest rates will lower economic growth.” This statement isa. a positive economic statement.b. a normative economic statement.c.untrue in every case.d.controversial, and so not a valid economic issue.19. The distinction between positive and normative economicsa.is that positive economics applies only to microeconomic problems.b.is that normative economics applies only to microeconomic problems.c.explains why economics is not a social science but a natural science.d.helps us to understand why economists sometimes disagree with one another.20. Which of the following is most closely associated with positive economics?a.Determining the impact of government spending on the actual level of totalemployment.b.Determining the best level of immigration into a country.c.Determining whether too many luxury goods are being produced.d.Determining whether or not the government should reduce poverty.21. In the diagram, the slope of the curve isa.increasing at a constant rate.b.increasing at a decreasing rate.c.decreasing at a constant rate.d.decreasing at an increasing rate.。
Supply and Demand Practice QuestionsQuestion 1: If the demand and supply curve for computers are:D = 100 - 6P, S = 28 + 3Pwhere P is the price of computers, what is the quantity of computers bought and sold at equilibrium.----Answer: We know that the equilibrium quantity will be where supply meets, or equals, demand. So first we'll set supply equal to demand:100 - 6P = 28 + 3PIf we re-arrange this we get:72 = 9Pwhich simplifies to P = 8.Now we know the equilibrium price, we can solve for the equilibrium quantity by simplifying substituting P = 8 into the supply or the demand equation. I'll substitute it into the supply equation:S = 28 + 3*8 = 28 + 24 = 52.Thus the equilibrium price is 8, and the equilibrium quantity is 52.Question 2. If we are looking at the market for cans of paint we know that the supply equation is as follows:QS = -5 + 2PAnd the demand equation is:QD = 10 - PThen to find the equilibrium pointWe set the two equations equal. Notice that quantity is on the left-hand side of both equations. Because quantity supplied is equal to quantity demanded at equilibrium, we can set the right-hand sides of the two equations equal.QS = QD-5 + 2P = 10 - P3P = 15P = 5At equilibrium, paint will cost $5 a can. To find out the equilibrium quantity, we can just plug the equilibrium price into either equation and solve for Q.Q* = QSQS = -5 + 2(5)QS = Q* = 5 cans。
关于供求关系的英语作文并举例说明英文回答：Supply and Demand.Supply and demand is a fundamental economic conceptthat describes the relationship between the availability of a good or service and the desire for it. It is represented graphically by two intersecting lines: the supply curve, which shows the relationship between the price of a good and the quantity supplied, and the demand curve, which shows the relationship between the price of a good and the quantity demanded.The equilibrium point on the supply and demand graph is where the quantity supplied equals the quantity demanded. At this point, the market is in equilibrium, and there is no tendency for prices to rise or fall.However, if the supply and demand curves shift, theequilibrium point will also shift. For example, if the supply of a good increases, the supply curve will shift to the right, and the equilibrium price will fall. Conversely, if the demand for a good increases, the demand curve will shift to the right, and the equilibrium price will rise.Supply and demand is a powerful tool for understanding how markets work. It can be used to predict price changes, analyze market trends, and make investment decisions.Here are some examples of how supply and demand works in the real world:The price of gasoline is determined by the supply of gasoline and the demand for gasoline. When the supply of gasoline is high, the price of gasoline will fall. When the demand for gasoline is high, the price of gasoline will rise.The price of housing is determined by the supply of housing and the demand for housing. When the supply of housing is high, the price of housing will fall. When thedemand for housing is high, the price of housing will rise.The price of food is determined by the supply of food and the demand for food. When the supply of food is high, the price of food will fall. When the demand for food is high, the price of food will rise.中文回答：供求关系。
