$23$ Plastic and steel are substitutes in the production of body panels for certain automobiles. If the price of plastic increases, with other things remaining the same, we would expect:

A$)$ the price of steel to fall.

B$)$ the demand curve for steel to shift to the right.

C$)$ the demand curve for plastic to shift to the left.

D$)$ nothing to happen to steel because it is only a substitute for plastic.

E$)$ the demand curve for steel to shift to the left.

$24$ Coffee and cream:

A$)$ are both luxury goods.

B$)$ are complements.

C$)$ are both more inelastic in demand in the long run than in the short run.

D$)$ have a positive cross price elasticity of demand.

$25$ Which of the following would shift the demand curve for new textbooks to the right?

A$)$ A fall in the price of paper used in publishing texts

B$)$ A fall in the price of equivalent used textbooks

C$)$ An increase in the number of students attending college

D$)$ A fall in the price of new textbooks.

Which of the following is NOT an assumption regarding people's preferences in the theory of consumer behavior?

A$)$ Preferences are complete.

B$)$ Preferences are transitive.

C$)$ Consumers prefer more of a good to less.

D$)$ All of the above are basic assumptions about consumer preferences.

The theory of consumer behavior is based on certain assumptions. The set of four basic assumptions includes:

A$)$ completeness.

B$)$ transitivity.

C$)$ intransitivity.

D$)$ Both A and B are correct.

E$)$ Both A and $C$ are correct.

The assumption of transitive preferences implies that indifference curves must:

A$)$ not cross one another.

B$)$ have a positive slope.

C$)$ be L$-$shaped.

D$)$ be convex to the origin.

E$)$ all of the above

A curve that represents all combinations of market baskets that provide the same level of utility to a consumer is called:

A$)$ a budget line.

B$)$ an isoquant.

C$)$ an indifference curve.

D$)$ a demand curve.

E$)$ none of the above

The slope of an indifference curve reveals:

A$)$ that preferences are complete.

B$)$ the marginal rate of substitution of one good for another good.

C$)$ the ratio of market prices.

D$)$ that preferences are transitive.

E$)$ none of the above