In 1972 federal vehicle emission standards allowed 3.4 hydrocarbons released per mile driven. By 2007, the standards allowed 0.8 hydrocarbons per mile driven. What was the rate of change from 1972 to 2007?

Question

anonymous · Answer

make 1972 your starting point so y=0 and then the hydro your x so x=3.4
then you have (3.4,0)

then 2007 is 35 years after 1972 so y=35 and x=0.8
(0.8,35)

then use then point slope formula

$$\frac{ y2-y1 }{ x2-x1 }$$
which will give you slope aka rate of change per year

anonymous · Answer

Would it be -2.6/35

anonymous · Answer

35/-2.6 you have your xs and ys mixed up (x,y) not (y,x)

anonymous · Answer

But you put y first in the formula

anonymous · Answer

yea and the y values are 35 and 0 so (35-0) goes on top

anonymous · Answer

In my textbook it has y first

anonymous · Answer

ordered pairs on a graph are (x,y) maybe you are reading it wrong?

anonymous · Answer

Would the answer be 35/-2.6

anonymous · Answer

yea after you divide it out