Which of the following is one of the main obstacles for macroeconomics research?

If the interest rate rises and the supply of dollars in the market for foreign currency exchange shifts left, then the price must have

a) dropped by less than 10 percent. b) remained constant. c) risen. d) dropped by more than 90 percent.

The opportunity cost of going to an outdoor music festival is

A) the value of the time spent at the festival. B) zero because there are no overhead costs for an outdoor festival. C) equal to the highest value of an alternative use of the time and money spent on the festival. D) the enjoyment you receive from going to the festival. E) the cost of the festival ticket only.