Marginal cost is the increase in the total cost of production to produce one additional unit. In this case, we want to determine the marginal cost of producing the fourth good. The total cost for producing three goods is 26 and the total cost for producing four goods is 29. Because total cost increases by 3, 3 is the fourth good's marginal cost.

The profit maximizing quantity for the production of goods is the level at which marginal cost equals marginal revenue. This table allows us to easily determine the marginal cost of producing the nth good, but it does not give any information about the marginal revenue associated with selling th nth good (i.e. market price of the good).

Opportunity cost is defined as the value of the best alternative that must be forgone in order to pursue a certain action. In this case, the best alternative to watching TV is babysitting, for which Hank would have been paid $7. Thus, the opportunity cost of watching TV is $7 for Hank.

Since he chooses to watch TV, the personal benefit associated with watching TV must be greater than $7 for Hank. 

Comparative advantage refers to the ability to produce goods at a lower marginal/opportunity cost than another party. Even if one party is better than the other at the production of all goods (absolute advantage), both parties will still gain by trading with each other because of comparative advantage. Thus, in this case, California must have the comparative advantage in producing strawberries, while Iowa must have a comparative advantage in producing corn.  While the two states may or may not have absolute advantages, we have no way of knowing with the information given.  More importantly, the question states that the advantage is based on opportunity costs.  Absolute advantage has nothing to do with this.

A public good is non-rival, which means that one person's consumption of the good does not affect another person's consumption of the same good.  Public goods are also non-excludable, which means that one person cannot prevent another from consuming the good. Among the choices here, the only answer that meets the criteria is the lighthouse, which is both non-rival and non-excludable.

Comparative advantage refers to the ability of a party to produce a particular good at a lower opportunity cost than another party. When trading, countries will always gain by trading the good in which they have comparative advantage in producing. Since the US is trading computers for cars from Germany, the US must have comparative advantage in computer production while Germany has comparative advantage in car production. 

Elasticity is a measurement used in economics to show the responsiveness of the quantity supplied of a good to a change in its price. Thus, a more elastic supply curve would cause a greater change in price as the quantity demanded increases.

The only factor that would cause a leftward shift of the supply curve of computers is the increase in wages for workers who manufacture computers. The other choices would result in a rightward shift of the supply curve. 

The difference between a consumer's willingness to pay and the actual market price of a product quantifies the consumer surplus associated with that product. It occurs when the consumer is willing to pay more for a product than its current market price. For example, if a consumer is willing to pay $3 for a cupcake, but its market price is $2, then the consumer surplus for him/her is $1. 

Monopolies often arise because of barriers to entry, which helps prevent firms from entering the market. Barriers to entry can enable one firm to dominate the market without the threat of competition from other firms.