Answer :
The population density of Western China is so low in comparison to Eastern China is due to most of its area is under mountainous.
Why population density of Western China is lower than in Eastern China?
The areas of western China have dramatic mountainous which make the livelihood of the region harsh that reduces its population. The agricultural yields also get destructed with low temperatures all around the year.
The population in Eastern China is more humid with sea and plane lands. Thus, living conditions are normal for survival making its population more than wester areas.
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