Exercise 58 Page 491

We want to identify the initial amount a and the growth factor b in the given exponential function. To do so, let's first recall the general form of an exponential growth function. y= a * b^x, where a>0 and b>1 Here, a is the initial amount and the base b is the growth factor, which equals 1 plus the percent rate of change expressed as a decimal. Let's now consider the given function. y= 0.2 * 5^x We see that a= 0.2 and b= 5. Therefore, the growth factor is 5.