Table of Contents

• Part I: Introduction
• 1: Word of the Day
• 2: Two bank accounts
• 3: Graphing your money
• 4: Graphing fruit fly populations
• 5: "Exponential" is not always "fast"
• Part II: Exponential Growth and Shrinkage
• 6: How to calculate next year's population
• 7: Using exponents
• 8: Problems using exponents
• 9: Negative rates = Shrinkage
• 10: Shortcut for exponential shrinkage
• 11: A quick review of exponential models
• Part III: Practice Problems
• 12: Drug dosage
• 13: Caffeine withdrawal
• 14: Growth of the computer industry
• 15: Viral growth
• 16: Wind energy
• 17: Ecology
• 18: Human population growth

Problems using exponents

Here are some more problems using the exponential formulation:

1. How much is a $26,000 retirement account worth after 40 years if it grows

   at 1%?

   at 5%?

   at 6%?

2. How many fruit flies do I have if I buy bananas (and 6 flies) on December 10th, but don't start zapping fruit flies until the day after Christmas (December 26th; growth rate = 30%)?:
3. Find out how much that $159 iPod will cost if you put it on your credit card and don’t pay anything for 10 years (19% interest)?
4. In 2008, the world’s population was about 7 billion.  Given current world population growth rate of 1.2%, what will population size be in 40 years? .