Context: A global city, Boston is placed among the top 30 most economically powerful cities in the world. Encompassing $363 billion, the Greater Boston metropolitan area has the sixth-largest economy in the country and 12th-largest in the world.

Question: What rank does Boston hold as far as being an economically powerful city in the world?
Answer: among the top 30

Question: What is the economy of Boston?
Answer: $363 billion

Question: What ranking in the country does Greater Boston metro hold as far as economy?
Answer: sixth-largest

Question: What ranking in the world does greater Boston metro hold as far as economy?
Answer: 12th-largest