Approximately 62.8 million americans, of the adult population — volunteer their time, talents, and energy to making a difference.

25%

Explanation:

Based on the information provided within the question it can be said that the approximate 62.8 million Americans account for roughly Twenty-Five percent of the adult population. Meaning that the entire adult population would sum up to be roughly 251.2 million individuals within the United States of America. Which only 25% volunteer their time, talents, and energy to making a difference.

true because they can bargain

this statement is true.

forests are public goods, available for everybody. when usage of such a good becomes interesting for consumers and its usage increases, there can be a risk of overexploitation. it is a non rival good therefore, if one person consumes the good it does not reduce the availability for subsequent consumers.

these caracteristics require the establishment of measures in order to prevent the destruction of a commonly owned space, for example, to restrict the amount of people that have access to the same time.