A model for the surface area of a human body is given by the function
$$
S=f(w, h)=0.1091 w^{0.425} h^{0.725}
$$
where $w$ is the weight (in pounds), $h$ is the height (in inches), and $S$ is measured in square feet.
(a) Find $f(160,70)$ and interpret it.
(b) What is your own surface area?