Answer Happy

This question is intended to assess your understanding of the stochastic general epidemic model. A stochastic general epidemic model is to be used to describe the progress of an infectious disease through a closed community of 28 people. Initially, there are two infectious individuals; the others are all susceptible. The contact rate 3 is 1.8 per day, and the removal rate is 1.2 per day. (a) Show that the epidemic parameter p is equal to 18. (b) Draw diagrams showing all the epidemic paths for which at most one person catches the disease before the epidemic dies out. Calculate the probability that of the initial 26 uninfected susceptibles, at most one person will catch the disease before the epidemic dies out. [1] [8] (c) Calculate an approximate value for the probability that there will be a major outbreak of the disease. [1]