Dealing with US Dollars...
Assuming we know the weights of half-dollars, quarters, dimes, nickels, and pennies.
Also assuming the weights remain constant (don't change from one quarter to another quarter).
If we have a bag of these coins (could include any coin), and we weigh them to get a total weight, can we know how much money we have in the bag?
If we cannot know exactly, how close of an estimate can we get?