Answer:
The answer is explained below.
Explanation:
Independent variable is the one that is changed and controlled: the <u>nail polish Sarah uses</u><u>.</u>
Dependent variable is the one that is studied, the result of the dependent variable: <u>how long the nail polish lasts</u>.
Hypothesis is the statement that has to be proved or declined during the experiment: <u>different nail polish lasts a different period of time without chipping</u>.
The control group is the not exposed to changes and the independent variable is part of this group: <u>when Sarah paints her nails</u> (4 Sundays in a row) and <u>the type of bottom coat and top coat</u> as well as the <u>weekly routine</u>.
The experimental group contains the independent variable and it is changed for the group: <u>the type of nail polish</u>.
The constants are <u>Sally</u> since she performs the experiment; the <u>period of research</u>, the routine and the coats.