Answer:
Western Russia is the most populated area. Northern Russia (Siberia) is the least populated. Western Russia is more populated due the Capital of Moscow being there, the climate is warmer, the land is better, there are more jobs as well. Northern Russia (Siberia) is essentially a frozen wasteland. Russia has traditionally exiled prisoners and insurrectionists there.
simply - those areas are warmer, have jobs, easier to live in those areas
Explanation: