To compare the growth rates of the functions \( g(x) = 1.3^x \) (exponential growth) and \( f(x) = 1.3x \) (linear growth), Austin should observe the steepness of the curves. The correct statement regarding their comparative growth rates is:
Austin should compare the steepness of the curves. The growth rate of \( f(x) = 1.3^x \) will quickly surpass the growth rate of \( g(x) = 1.3x \).
This means he will notice that the exponential function \( f(x) = 1.3^x \) grows much faster than the linear function \( g(x) = 1.3x \) as \( x \) increases.