The answer is positively correlated
Explanation:
If university graduates typically earn more money than high school graduates, this would indicate that the level of education and income are positively correlated.
Case studies are not replicated and single case study cannot be generalized to a wider population. The limitation is there is a potential risk for researcher bias in case studies.
People with their wealth and aggressiveness of their children are negatively correlated.
The researcher decides to measure intelligence by the number of seven Dwarfs that names correctly is known as questionable validity.
