Consider Example 5.3.13. Consider a D/M/2 queueing system with $W_s=1$ second and $\rho=0.9$ so that $\lambda=1.8$ customers per second. Calculate the performance parameters $W_q, W, L_q, L$, the distribution function for $w$, and $\pi_w[90]$, assuming
(a) $\omega=e^{-0.2}$ (Halachmi's approximation), and
(b) $\omega=0.80689933$ (the correct value).