Answer:
independent variable: size of soccer ball
dependent variable: period of time the balls stay in the air
control variable: parts of the body used to juggle the ball
Step-by-step explanation:
The independent variable is the manipulatable variable supplied into an experiment. It is a variable that directly affects the dependent variable.
The independent variable is the outcome variable. It is the variable that is primarily measured from experiments whose value depends on the value of the independent variable.
The control variables are those that are kept constant throughout the course of experiments. In other words, they do not directly affect experimental outcomes.
Hence, in the illustration;
independent variable: size of soccer ball
dependent variable: period of time the balls stay in the air
control variable: parts of the body used to juggle the ball