SOLUTIONS MANUAL for Stochastic Modeling: Analysis and ...
SOLUTIONS MANUAL for Stochastic Modeling: Analysis and ...
SOLUTIONS MANUAL for Stochastic Modeling: Analysis and ...
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32 CHAPTER 5. ARRIVAL-COUNTING PROCESSES<br />
(b) The expected time between arrivals is<br />
1/λ =1/2 hour<br />
Let G be the gap between two successive arrivals. Then G is exponentially distributed<br />
with λ =2.<br />
Pr{G >1} = 1− Pr{G ≤ 1}<br />
= 1− (1 − e −2(1) )<br />
= e −2<br />
≈ 0.135<br />
(c) Because of the memoryless property<br />
E[R 0 ]=E[G] =1/2 hour<br />
Pr{R 0 ≤ 1/4} =Pr{G ≤ 1/4} =1− e −2(1/4)<br />
≈ 0.393<br />
(d)<br />
Pr{T 13 ≤ 7} =1−<br />
12 ∑<br />
j=0<br />
e −2(7) (2(7)) j<br />
j!<br />
≈ 0.641<br />
(e) Let λ 0 be the arrival rate <strong>for</strong> urgent patients.<br />
λ 0 =0.14λ = 0.28 patients/hour<br />
Pr{Y 0,12 > 6} = 1− Pr{Y 0,12 ≤ 6}<br />
6∑ e −0.28(12) (0.28(12)) j<br />
= 1−<br />
j!<br />
j=0<br />
≈ 0.055<br />
(f) Let λ 2 be the overall arrival rate.<br />
λ 2 = λ +4=6/hour