Marcos's study suggested that elementary students who watch tv more than three hours a day are more likely to be overweight than students who watch less tv. in this study, students' weight is:

From the question given it is clear that students’ weight, in this research, functions as the dependent variable.

The research that Marco is conducting is an experimental study, since he wishes to know whether the length of time the children spent watching television would influence their body weight. In this case, the independent variable is the TV-watching time while the dependent variable is the body weight.

the answer is d. amendments.

changes in factors like average income and preferences can cause an entire demand curve to shift right or left. this causes a higher or lower quantity to be demanded at a given price. demand curves relate the prices and quantities demanded assuming no other factors change. it is important for consumers to know this information, because it is crucial for them to know what they can afford and can't afford. i hope this .