1. Growth and Decay: Rational Exponents
In the previous section we considered growth and decay using integral exponents.
Although a graphing calculator easily gives an approximate value of $4.18, there remains the question of what a fractional exponent means.

4. Example 2. Suppose a car presently worth $8200 depreciates 20% per year. About how much will it be worth 2 years and 3 months from now?
2 years and 3 months = 2.25 years.
It will be worth about $4963.

7. Example 5. A house bought five years ago for $100,000 was just sold for $135,000. To the nearest tenth of a percent what was the annual growth rate?
To the nearest tenth of a percent, the growth rate was 6.2%