The correct statement describing how Austin should compare the growth rates of \( g(x) = 1.3x \) and \( f(x) = 1.3^x \) is:
"Austin should find where one curve is above the other curve on the graph. The growth rate of \( f(x) = 1.3^x \) is only greater than the growth rate of \( g(x) = 1.3x \) to the right of their right-most intersection point."
This option correctly acknowledges that while \( f(x) = 1.3^x \) (an exponential function) grows more rapidly than \( g(x) = 1.3x \) (a linear function) as \( x \) increases beyond a certain point, the two functions intersect at some points before \( f(x) \) outgrows \( g(x) \) for larger values of \( x \). Thus, examining where one function is above the other, particularly after their last intersection, would provide insight into their growth rates.