Macroeconomics 20th Edition by Campbell McConnell,Stanley Brue,Sean Flynn

تمرين 25

Graph and label as either direct or indirect the relationships you would expect to find between (a) the number of inches of rainfall per month and the sale of umbrellas, (b) the amount of tuition and the level of enrollment at a university, and (c) the popularity of an entertainer and the price of her concert tickets.