One tank of goldfish is fed the normal amount of food once a day, a second tank is fed twice a day, and a third tank four times a day during a six week study. what is the independent variable, the dependent variable, the control group, and the constant?

In the experiment involving the goldfish, we have:

Independent variable: number of times the fish is fed per day.Dependent variable: weight or growth of fish.Control Group: first tank of goldfishConstant: tank size

Note the following points:

Two types of variables in mostly all scientific research studies are dependent and independent variables.Independent variable is the variable that is being manipulated or changed by the researcher in an experiment.The dependent variable is the variable the researcher studiesThe independent variable is the "cause".The dependent variable is the "effect".When the researcher manipulates or changes the independent variable, the independent variable changes.The dependent variable is dependent on the independent variable.Control group is the group of research subject that is used to compare the effect of a treatment to the experimental group(s) that receives the treatmentConstant in an experiment is the variable that remains unchanged for all research subjects.

In the experiment cited above:

The independent variable is the amount of times the fish is fed a day. This is what the researcher changes.The dependent variable can be the weight or growth of the fish that the researcher measures.The control group is the fish in the first tankThe constant could be the size of tank or temperature of water that is kept the same for all units.We can state that the growth or weight of the goldfish is dependent on the number of times they are fed in a day.

Therefore:

Independent variable: number of times the fish is fed per day.Dependent variable: weight or growth of fish.Control Group: first tank of goldfishConstant: tank size.

Learn more here:

link

Very hard to understand