How to find the percentage you need to divide 129$ with 240$. You get 0,5375 and multiply that with 100 to get the percentage, wich is 53,75%.
How to know if this is correct is to think we know the price in 2000 and the percantage but not the price today. So then we take 240$ multiply with 0,5375, and get 129$. Now you know this is correct.
