Radioactive substances emit -particles. The number of such particles reaching a counter over a given time period follows the Poisson distribution. Suppose that two substances independently emit -particles. The rst substance emits -particles that reach the counter according to a Poisson (2.8) distribution. The second substance emits -particles that reach the counter according to a Poisson (6.5) distribution.
(a) Find the mode of the number of particles to hit the counter.
(b) Find the chance that at most 5 particles hit the counter.
(c) Suppose that counts are recorded for 100 independent time periods. Estimate the chance that that at most 5 particles hit the count at most 7 times.