Chapter 4.3, Problem 161E

A Cobb-Douglas production function

$f\left(x,y\right)=200x^{0.7}{y}^{0.3}$ where x and y represent the amount of labor and capital available. Let x = 500 and y=1000. Find $\frac{\delta f}{\delta x}$ and $\frac{\delta f}{\delta y}$ at these values, which represent the marginal productivity of labor and capital, respectively.