Final answer:
A public good is a good that is nonexcludable and non-rival. In the given scenario, both Dmitri and Jake will benefit from the contributions made by the other person to the building mural.
Step-by-step explanation:
A public good is a good that is nonexcludable and non-rival. Nonexcludable means that it is difficult or costly to prevent someone from using the good, and non-rival means that one person's use of the good does not diminish its availability to others. An example of a public good is national defense, which protects everyone and cannot exclude anyone from its benefits.
In the given scenario, the creation of a building mural is considered a public good. Both Dmitri and Jake will benefit from the contributions made by the other person because the mural is nonexcludable and non-rival. Their combined benefit is maximized when both of them contribute to the building mural, as shown in the upper left cell of the table.