6. A fire station has tabulated the amount of time between emergency calls. Nine

Question

6. A fire station has tabulated the amount of time between emergency calls. Ninety percent of the calls come within 6 hours of the last call. If the occurrence of the emergency calls has a Poisson distribution with constant , find and give its units. 7. Suppose X-poisson (2), then EX-Var(X)-·when you try to fit a Poisson model, it cannot adjust the variance independently of the mean since there is only one free parameter here. This is called the Over- dispersion problem for a Poisson model. Will you have the same problem if you want to fit a binomial model? Why? Note: We don't need to care about the exact methods of fitting the above models or why do we want to adjust the variance independently of the mean so far. We only focus on this phenomenon with respect to some properties of these two distributions.

Explanation / Answer

Given is an exponential distribution, therefore
f(X <= 6) = 1 - e-*x = 1 - e-*6 =0.9
e-*6 =0.1
-*6 = ln(0.1)
= 0.38376 calls/hour

Related Questions

Navigate

• Browse (All)
• Browse 6
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.