Question 78570
using the graphing technique we TWO POINTS (0,1800) & (3.25*5280,0)
OR (0,1800) & (17160,0) 
NOW WE FIND THE SLOPE BETWEEN THESE TWO POINTS THUS:
(0-1800)/(17160-0)=-1800/17600=-.1022727 FOR THE SLOPE OR (.10).