Q3. Let N(t) be a Poisson process (N(0) = 0). The Poisson process is an independent increment process. The two key properties of the process are:
Property 1: Consider any interval [t1,t2] such that t2 > t1. Then, the number of arrivals in the interval [t1,t2] follows a Poisson distribution with parameter Ī»(t2 - t1), i.e., N(t2) - N(t1) ~ Poisson(Ī»(t2 - t1)).
Property 2: Consider any two non-overlapping intervals, i.e., for any t1 < t2 < t3 < t4, [t1,t2] and [t3,t4] are disjoint. Then, N(t2) - N(t1) and N(t4) - N(t3) are independent.
Show that for s = t/6, the conditional distribution of N(s) given N(t) = n is binomial with parameters n and p = 1/6, i.e., P(N(s) = m|N(t) = n) = (n over m)(1 - p)^{n-m}p^m.