Chapter 7 - Exponents and Exponential Functions - 7-7 Exponential Growth and Decay - Practice and Problem-Solving Exercises - Page 459: 25

Initial Amount: 100 Decay Factor: $\frac{2}{3}$

To find the initial amount, plug 0 in for x: g(x) = 100($\frac{2}{3}$)$^{x}$ g(0) = 100($\frac{2}{3}$)$^{0}$ g(0) = 100(1) g(0) = 100 $\frac{2}{3}$ is the decay factor because this is the value that is attached to the "x" exponent. In other words, this is the value that will determine by how much x decays.