To accurately compare the growth rates of the functions \( g(x) = 1.3^x \) and \( f(x) = 1.3x \), Austin should focus on the behavior of these two functions as \( x \) increases.
The correct observation is that the exponential function \( g(x) = 1.3^x \) grows much faster than the linear function \( f(x) = 1.3x \) for large values of \( x \). Initially, for smaller values of \( x \), \( f(x) \) may be greater than \( g(x) \), but as \( x \) increases, \( g(x) \) will eventually surpass and then continue to grow faster than \( f(x) \).
Therefore, the correct choice among the provided responses is:
Austin should compare the steepness of the curves. The growth rate of \( g(x) = 1.3^x \) will quickly surpass the growth rate of \( f(x) = 1.3x \).
This statement correctly describes how to compare the two functions and what observation he should expect regarding their growth rates.