In a branching process, an individual has 0, 1 or 2 descendants with probability 1/4, 1/4, 1/2, respectively. Start the process at generation 0 with a single ancestor. Compute the expected population size at generation 3. Write an expression for the probability that the branching process dies out at or before generation 4. Do not evaluate. Compute the probability that the branching process ever dies out. Compute the probability that the process dies out conditioned on the event that the population at generation 3 consists of 4 individuals