New Estimations of Fixation Time Mean for Populations with Fixed Size

The population consisting from $N$ of particles is considered, each of which attributes some type. All particles during the integer moments of time perish and generate a random number of particles of the same type, as the parent. Thus population keeps the size $N$, and the casual vectors setting number of posterity from each particle, have the distributions independent concerning any shifts of coordinates. Justice of the top estimation based on decomposition of function $v (k)$ under the Taylor formula to within 5 moments is proved. Conditions at which the new estimation improves earlier known are resulted.