Which of the following is the most liquid store of purchasing power?

Prices of commercial airline tickets (assume that this is a normal good) have fallen in recent months. Over this same period, the price of jet fuel has risen and consumer incomes have fallen

Which of the following best explains the falling prices of airline tickets? A) The supply curve for airline tickets has shifted to the left while the demand curve for airline tickets has shifted to the right. B) The demand curve for airline tickets has shifted to the left more than the supply curve has shifted to the left. C) The supply curve for airline tickets has shifted to the left more than the demand curve has shifted to the left. D) The demand curve and the supply curve for airline tickets have both shifted to the right.

Graphically, the average productivity of labor would be illustrated by the slope of the marginal productivity curve at the relevant point

a. the slope of the total product curve at the relevant point. b. c. the negative of the slope of the marginal productivity curve at the relevant point. d. the slope of the chord connecting the origin with the relevant point on the total output curve.