With the collapse of house prices that started in 2006, the American Dream has become a nightmare

Question:

With the collapse of house prices that started in 2006, the American Dream has become a nightmare for many of the 75 million Americans who own a home (CBS Evening News, February 2, 2010). However, the drop in house prices has not been uniform across the country. The accompanying table represents median home prices (in $1,000s) by region for 2007, 2008, and 2009.

a. Use 2007 as the base year to construct a simple price index for each region.
b. Use the percentage decline in home values to discuss regional differences in price drops.