a) What are the explanatory and response variables?
Percentage of people with a bachelor’s degree (in the county) is the explanatory variable.
Per capita income (in the county) is the response variable.
b) Describe the relationship between the two variables. Make sure to discuss unusual observations, if any.
There is a positive association.
The higher the percentage of people with a bachelor’s degree in a county, the higher the income per capita in the county.
c) Can we conclude that having a bachelor’s degree increases one’s income?
We cannot because it is an observational study, so we cannot infer causation.