  This paper presents description of time evolution of averages of Markov
process in wide range of noise intensity. Exact expression of time scale of
average evolution has been obtained. It has been demonstrated numerically that
for purely noise-induced transitions (transitions over potential barriers) the
time evolution of mean coordinate is a simple exponent with a good precision
even for the case when the potential barrier height is comparable or smaller
than the noise intensity. Also it has been demonstrated that nonlinear system
may be "linearized" by a strong noise.
