If the price of gold decreases at a monthly rate of 2.9%, by what percentage does it decrease in a year?
Hmm, that can't be right. It doesn't compound! :O
The amount that you start with is 100%.
If this decreases, you will have only 100% - 2.9% = 97.1% of the original amount.
Going from month to month, although the price decreases by the same percentage each month, it doesn't
decrease by the same dollar amount.
To find how much you will have left after 12 months of decreases, you need to find: (0.971)12 = 0.7025,
which means that you have decreased by 100% - 70.25% = 29.75%.