3.    A researcher examines whether length of daily exposure to a sun lamp (0 minutes, 30 minutes, or 60 minutes) influences self-reported depression (measured as either “depressed” or “not depressed”).

1.    What is the independent variable?

2.    Is the independent variable manipulated or not manipulated?

3.    How many levels are there for the independent variable?

4.    What is the dependent variable?

5.    What is the scale of measurement for the dependent variable?