3. Michael Bloomberg:

The current Mayor of the New York City, Michael Bloomberg is also an American Businessman and as well as a politician. He is the 11^th richest person in the United States with a net worth of $22 billion in 2012. He is the founder as well as the 88 percent owner of the financial data-services firm Bloomberg L.P. As he came from a middle class background, he had to work to pay his tuition fees every month and this reason made him to work as a parking lot attendant to earn money to pay his fees. He completed his Master’s degree in Business Administration from the Harvard University and also before that he completed his Bachelor’s Degree in electrical engineering field.

He is also been termed as the 20^th richest person in the world. The drastic change in his total wealth came in just 2 years span from March 2007, March 2009 where he moved on in the wealth raking list from the 142^nd place to 17th place.