provide a measurement for the following "Research question: How does the level of education impact the level of income? Theory: the level of education does affect the income levels. Education is my primary independent variable. The higher educated people have higher income levels as when people are more educated, they will have more opportunities to apply for higher maintenance jobs, resulting in higher paying income. Hypothesis: the higher level of education, the higher level of income Confounding variables: Immigrants and Citizenship: for some positions, if you have the citizenship of the country, then you will be able to apply for those high paying jobs as those jobs only accept the people who have the citizenships of the country Language: language barriers could limit job opportunities, which result in lower income (doesn't matter what level of education that person has in their own country)