Chapter 5 - Exponential Functions - 5.5 Exponential Growth and Decay Rates and Compounding Interest - 5.5 Exercises - Page 469: 2

$7\%$ growth.

Growth or decay rate $r=b-1$ where $r$ is a percentage written as a decimal and $b$ is the base of an exponential function of the form $f(x)=a\cdot b^{x}$. Given $f(x)=20(1.07)^{x}$ $\implies b=1.07$ $r=b-1=1.07-1=0.07$ Or $r=0.07\times100 \%=7\% $ $r$ is positive. So, there is $7\%$ growth.