Answer:
Hours of sleep of college students
Explanation:
In a typical experiment or scientific study, there are usually two types of variables that gives the study direction. We have dependent and independent variable.
The independent variable which is the “cause”, is the variable that can be manipulated by the researcher to find the possible effect it would bring on a dependent variable.
The dependent variable which is the “effect”, is the variable that changes as a result of the manipulation of the independent variable. It is dependent on the independent variable.
In the study conducted by the psychologists, the independent variable is the hours of sleep of students, which has a direct effect on the grades achieved by students (dependent variable). The grades achieved by students (dependent variable) is dependent or determined by the hours of sleep (independent variable) of students.