I want to know the answer to the following question:
In terms of purchasing power, where did Miami rank among world cities in a 2009 UBS study?
All the background I'm provided with is that "In a 2009 UBS study of 73 world cities, Miami was ranked as the richest city in the United States (of four U.S. cities included in the survey) and the world's fifth-richest city, in terms of purchasing power.". Is that enough to answer the question?