Shift to the left or right for supply: number of sellers increases

Which of the following will lead to a decrease in the value of Spanish income per capita in dollars?

A) An increase in the value of the Spanish income per capita in Euro B) A decrease in the dollar/euro exchange rate C) An increase in the dollar/euro exchange rate D) A decrease in the income per capita of U.S.

Which of the following statements is TRUE?

a. Average cost (AC) is irrelevant to extent decisions b. Average cost determines how much you produce c. Marginal cost (MC) is irrelevant to extent decisions d. All of the above