Which is the best sociological research method to use?

The simple interest on a loan of 200$ at 10% per year is

Sam and ben have discovered some strange animals living in the woods behind their house. ben is excited because he believes they are marsupials, an animal he's never observed in the wild before. his brother is sure it is not. what feature should the boys consider in deciding whether the animals are marsupials?

On a production possibility curve, data points that fall outside of the curve represent what