SOLUTION: The population of a Midwestern city decays exponentially. If the population decreased from 900,000 to 800,000 from 2003 to 2005, what will be the population in 2008?

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: The population of a Midwestern city decays exponentially. If the population decreased from 900,000 to 800,000 from 2003 to 2005, what will be the population in 2008?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 1024605: The population of a Midwestern city decays exponentially. If the population decreased from 900,000 to 800,000 from 2003 to 2005, what will be the population in 2008?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The population of a Midwestern city decays exponentially. If the population decreased from 900,000 to 800,000 from 2003 to 2005, what will be the population in 2008?
-------
Let 2003 be the zero year; then 2005 is the three year, and 2008 the 5 year.
---------------
P = ab^x
---
P(3) = ab^3 = 800000
P(0) = ab^0 = 900000
---
a = 900000
Solve for "b"::
b^3 = 8/9
b = 2/cbrt(9)
----
Equation::
P(x) = 900000^x
----
Ans: P(5) = 900000