Please help me marking brainlist

Stu and ambrose are working together on a study of whether diet is related to students' mental health. first, they randomly select 10 students from the student center and 10 students from the office of counseling and psychological services. then, they ask students to rate their diet in terms of healthiness on a scale of 1-100 before completing a 20-item mental health survey. a) name one of the constructs being studied b) how was the construct you named above operationally defined in this experiment? e) was the variable you described above their independent variable, their dependent variable, or a controlled variable? d) what is a confounding variable? what is a potential confound in this study?

The center on a target has a diameter of 5 inches. the whole target has a diameter of 25 inches. complete the explanation for what part of the whole target is the center. the center of the target takes up % of the whole target.

The hockey team has been great! in 2008, they won 20% more games than in 2007 in 2009 they won 50% more games than in 2008 what was their overall percentage increase from 2007 through2008?