In each of the following experiments, identify the independent variable, the conditions of the independent variable, and the dependent variable:
(a) Studying whether scores on a final exam are influenced by background music that is soft, loud, or absent.
(b) Comparing freshmen, sophomores, juniors, and seniors with respect to how much fun they have while attending college.
(c) Studying whether being first born, second born, or third born is related to intelligence.
(d) Examining whether length of daily exposure to a sun lamp (15 minutes versus
60 minutes) alters self-reported depression.
(e) Studying whether being in a room with blue walls, green walls, red walls, or beige walls influences the number of aggressive acts produced by adolescents.