A Poisson Process is remarkably scalable.
9 patients in 3 hours ==> 3 patients in 1 hour.
p(0|Poisson with mean = 3)
A doctor receives on an average 9 patients in his visiting hours from 6pm to 9pm. Find the probability that on an arbitrary date he will sit idle between 7pm and 8pm.
Please help me in solving this problem.