Which of the following is not an example of a graph of a single variable?

Refer to Table 11-2. What is the marginal product of the 4th worker?

A) 230 bushels B) 57.4 bushels C) 50 bushels D) 12.4 bushels

When members of Congress vote to pass new legislation, they will

A) fail to consistently represent the underlying preferences of voters. B) always vote for the alternative favored by a majority of the voters. C) always fail to represent the underlying preferences of voters. D) always vote for the alternative favored by a plurality of the voters if there is no majority position.