a) Read the county level asthma data in asthmanc.txt. 
   File 'nc2010econ.txt' are selected economic, educational, and demographic data for North Carolina at the county level.
   The list of variables in given in the file NC2010econ.variables.

b) Read in these related economic variables and create a dataset.
c) Merge these two datasets by county name.
d) The main task of the assignment is to look for a linear statistical relationship between asthma and one or more of the economic variables.
  (PROC REG or PROC GLM)
Note:
1) Be aware that many counties in North Carolina are quite small, both in area and population, and so that analysis of count 
   data requires care. My suggestion is to limit your analysis to the largest counties, avoiding the smallest.
2) You should be aware that the largest counties have the largest counts, the smallest counties the smallest -- of anything -- 
   regardless of cause/effect. For example, Mecklenberg and Wake counties have the highest numbers of doctors and the highest 
   incidence of cancer while Camden and Clay counties have small numbers of both. But does this apparent positive correlation here 
   mean that we should try to reduce the number of doctors to reduce cancer incidence? Base any relationship on RATES: number/population
   (in this case, 'rate' or 'yrate')