By studying ancient civilizations, such as the greek and roman empires and the angkor civilization of southeast asia, historians have concluded that these civilizations declined partly because of:

Many historians have concluded that the collapse of these societies is due to environmental destruction for the rapid growth of the populations.

Explanation:

Specifically, many studies have been carried out, and even mathematical models to study the similarities in the causes of collapses and falls of great empires and civilizations such as the Greek, Roman and Angkor among others. With all these studies it has been determined that the main reason for the fall of these empires is directly related to the rapid growth of the population and the slow development of resources (agriculture and resources to survive); what has triggered serious economic and political problems too.

part a. there were 250 teenagers surveyed (100% of tenagers = 250)therefore 1 % = 250/100 = 2.5 76% = 1% x 76 = 2.5 x 76 = 190 teenagers of the 250 surveyed liked burgerspart b: jane surveyed 25% (which is equal to 50 teenagers, i.e. a quarter of the teenagers surveyed is 50) to get 100% we simply get 4 quarters, i.e. multiply 50 by 4 = 200 teenagers were surveyed by jane. part c: it is impossible to give an example where a percentage is greater than 100%, since, by definition , percentage means "per 100".