2.2. A pure death process starting from X(0) = 3 has death parameters Ao = 0, , = 3,A2= 2,A3 = 5. Let W, be

2.2. A pure death process starting from X(0) = 3 has death parameters Ao = 0, μ, = 3,A2= 2,A3 = 5. Let W, be the random time that it takes the process to reach state 0.

(a) Write W, as a sum of sojourn times and thereby deduce that the mean time is E[W,] = o.

(b) Determine the mean of W, + W, + W,.

(c) What is the variance of W,?