Marshall's mistake lies in the fact that he is only considering a small portion of the domains of the functions. If he went farther to the right on the graph, he would observe that the growth rate of \( f(x) = 6 \cdot 1.5^x \) eventually surpasses the growth rate of \( g(x) = 5x + 10 \) for large values of \( x \).
So, the correct response is:
Marshall is only considering a small portion of the domains of the functions. If he went farther to the right on the graph, he would observe that the growth rate of \( f(x) = 6 \cdot 1.5^x \) eventually surpasses the growth rate of \( g(x) = 5x + 10 \) for large values of \( x \).