Hills Lighting believes that several factors influences light fixture sales.

Here is your data set for this problem:

Sales      Advertising         Price      # XXXXX stores
41           20                           40           1
42           40                           60           3
59           40                           20           4
60           50                           80           5
81           50                           10           6
80           60                           40           6
100         70                           20           7
82           70                           60           8
101         80                           30           9              
110         90                           40           10

Hills Lighting believes that several factors influences light fixture sales.   Sales are in thousands, advertising are in hundreds of dollars, and price is the unit retail price.  Estimate a simple linear regression that only involves sales and advertising.  Interpret the slope coefficient as well as R square.  Show all work.

• Estimate a multiple linear regression using all the data.    Interpret the slope coefficient, R square, and the adjusted R square.  Show all work.