What is the manipulable (independent) variable in an experiment in which the size of the wheels are changed and the resulting speed of the skateboard down a ramp is measured? Select one: a. The weights on the skateboard b. The height of the ramp c. The speed of the skateboard down the ramp d. The size of the skateboard wheels Clear my choice

In an experiment, the independent variable is the variable that the experimenter manipulates or changes intentionally in order to effect a measurable response in another variable.

In this experiment, size of the wheels are changed and the resulting speed of the skateboard down a ramp is measured. This means that the independent variable is the SIZE OF THE SKATEBOARD WHEELS because it is what the experimenter changes to determine the speed of the skateboard (dependent variable).