How did this invention the qin to conquer the rest of china?

The Qin introduced common coinage, meaning a form of ´fiat´ currency backed by the central government. It was called a ´ban liang´, and they could be issue by local nobles as well as by the emperor. A system of coinage is important for the unification of a massive empire because it facilitates trade and the recollection of revenue for the central government. As such, it becomes easier to raise a common army, which is essential for unification of different warring states.

the rebels’ chances of victory at lexington & concord were fairly slim, given the fact that most of them very untrained and they were up against the world's greatest military force.  

well considering i can't see the graph, it's probably prices