Answer:
Independent variable: Glass of milk
Dependent variable: Time of sleep
Control variable: same type of milk
Explanation:
Independent variable in an experiment refers to the variable that the experimenter manipulates or changes in order to get a response in another variable (dependent). In this case, the independent variable is the GLASS OF MILK taken before bed.
Dependent variable is that variable that is measured in an experiment. It is the variable that responds to the changes made to the independent variable. In this experiment, the dependent variable is the TIME OF SLEEP of the students.
A control variable or constant is the variable that is kept unchanged throughout the course of the experiment in order not to alter the outcome of the experiment. In this experiment, a control variable can be the SAME TYPE OF MILK taken by each student.
