Given the enhancement-type NMOS transistor shown in Eigure P10.11. compute $R_1, R_2, R_S$ and $R_D$. Let $I_D=4 \mathrm{~mA}, V_D=9 \mathrm{~V}, V_{D S}=4.5 \mathrm{~V}, V_{D D}= 18 \mathrm{~V}, V_t=4 \mathrm{~V}, K=0.625 \mathrm{~mA} / \mathrm{V}^2$, and maximum total dissipated power $P_{T, \text { max }}=75 \mathrm{~mW}$.