LetZ0,Z1,...beabranchingprocesswhoseoffspringdistributionmean is ?. Let Yn = Zn/?n, for n ?= 0. Show that E(Yn+1|Yn) = Yn.

3. Let Zo, Z1, . .. be a branching process whose offspring distribution mean is M. Let Yn = Zn/u", for n * 0. Show that E(Ynti|Yn) = Yn