Why this chapter matters
Repeated percentage change appears in population, depreciation, spread, and many science applications where a linear model fails.
What you will learn
- Identify constant difference versus constant ratio patterns.
- Write and interpret y = a(b^x) growth and decay models.
- Use tables, graphs, and residual thinking to evaluate a simple model.
Lessons in this chapter
- Linear versus exponential changeCompare additive and multiplicative patterns.
- Growth and decay modelsInterpret initial value and growth factor.
- Reading exponential graphsConnect intercepts and long-run behavior to context.
- Choosing a modelCheck whether data support a linear or exponential relationship. Read the full guide →
Study task
Compare a savings plan that adds $50 monthly with one that grows by 5% per period. Explain when each model is appropriate.
Chapter checkpoint
A quantity starts at 200 and grows by 8% each period. Write its model.
Use y = 200(1.08)^x, where x is the number of growth periods.