The Hughes family and the Sanders famlly each used their sprinklers last summer. The Hughes family's sprinkler was used for 20 hours. The Sanders family's sprinkler was used for 30 hours. There was a combined total output of 1500 L of water, What was the water output rate for each sprinkler if the sum of the two rates was 55 L per hour? Hughes family's sprinkler: Sanders family's sprinkler:

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?