Since the graph of f(x) is translated 1 unit down, we need to decrease the value of f(x) by 1 to find g(x):
[tex]\begin{gathered} g(x)=f(x)-1\\ \\ g(x)=3|x|-4-1\\ \\ g(x)=3|x|-5 \end{gathered}[/tex]Now, to calculate the rate of change over the interval 2 <= x <= 5, we can use the formula below:
[tex]\begin{gathered} rate=\frac{g(5)-g(2)}{5-2}\\ \\ g(5)=3\cdot5-5=10\\ \\ g(2)=3\cdot2-5=1\\ \\ rate=\frac{10-1}{3}=\frac{9}{3}=3 \end{gathered}[/tex]Therefore the rate of change is 3.