I need some help with this math problem:

Let n be the number of oil refineries at t years since 2005. A reasonable model of oil refineries is n= -2.23t + 210.53. What is the slope of this model? What does it mean in this situation?

1 answer

recall that the slope-intercept form of a line is

n = mt+b

where m is the slope. Here, that is -2.23

It means that the number of refineries is declining by 2.23 per year, or about 9 refineries every 4 years.