Answer:
1: There is a strong, negative correlation
2: The lower the standard of living, the higher the family size on average
3: In my opinion, the rise of living standards comes first, as in many countries with a low standard of living there is often child labour, and people tend to have more children so that they can work and earn money for the family. Therefore, if the living standards get better, there will be less of a need for this to happen.
4: 0
5: As the world collectively gets better developed, population growth may slow down as people may have less children.