Consider the Cobb$-$Douglas production function

$f(x,y)=200x^{0\mathrm{.}65}{y}^{0\mathrm{.}35}$

When $x=4500$ and $y=900,$ find the following. $($Round your answers to two decimal places.$)$

$($a$)$ the marginal productivity of labor, del$\frac{f}{d}$elx

$($b$)$ the marginal productivity of capital, del$\frac{f}{d}$ely