A research team is interested in the relationship between income and intelligence. They recruit 50 elementary school students. In the first part of the study, the participants are ranked on their household income (low to high), 1-50. When the students are seniors in high school, an intelligence test is administered. The investigators rank their performances on the test (low to high) 1-50. Finally, the researchers evaluate the relationship between the two sets of ranks.

1. State whether the design is a true experiment or a correlation.

2. State the Independent or Predictor variable (each study has one or the other).

3. State the Dependent or Criterion variable (each study has one or the other).