find a formula for modelling tonnage, given two points

[chele]

Solid waste in millions of tons was 205.2 in 1990 and 229.2 in 2001. Assume there is a linear function, find a formula by finding the equation of the line through these two points.

I got the answer as a change of rate with 2.18 millions of tons/year and can make both a graph and a table but I need to find a formula. Can someone show how to do this or at least what formulas I need to put in the equation?

 

[tkhunny]

Re: find a formula

Independent Variable: Year
Dependent Variable: Tons o'Stuff

Two-Point Form

y-k = m(x-h), where m = (change in y)/(change in x) = slope and (h,k) is any point on the line.

m = (229.2-205.2)/(2001-1990) = 24 / 11 = 2.18

y-229.2 = 2.18(x-2001)

If you don't know the form, you can't do it.

 

[chele]

Re: find a formula

thanks...got the answer later