Passengers on a train or example of an aggregate group

Yes, indeed.

Explanation: You must first know that an "aggregate group" it´s a group of people that should be called an organization. Why? Because it´s a group that lies on a certain ( all the members in the same place) ubication with a certain task or purpose to develop. The name given to these groups doesn´t assume the succes of the entrusted task.

using the scientific method.

all cities have a governor

all cities are in states or provnies then country

all cities have people

difference

some are rich

some are poor

some are average