1. The problem statement, all variables and given/known data - The following table gives the population of a city over time: 2. Relevant equations I know this equation: y = a(b)x and exponential growth: b = 1 + growth rate and b = 1 - decay rate 3. The attempt at a solution I know from back in chapter 2 that first differences = linear model, second differences are the same = quadratic and if the 3rd differences are the same then its a cubic model...but that doesn't work here. I am completely stuck....how do I find the model. Any hints/tips/methods will be greatly appreciated!! Thanks!!