3. Census tracts are spatial areas with about 5,000 people each and varying areas. Using the data on Chicago census tracts for 2010 (included on the spreadsheet Census Tract Data, downloadable from Blackboard), estimate a density gradient for Chicago in 2010. In particular estimate y, from the equation: Ig Density = lg (Do)- yx, where x is distance in miles from the CBD. 4. Write a brief description of the equation you estimated and include a graph showing the original 2010 data and your regression line. In your description include a transformation of your equation to the form: Density (Do)e- 5. What density does your equation predict for the center of Chicago (i.e. x=0)?