Alex wanted to find out what toothpaste made teeth the cleanest. Everyday she brushed her teeth with a different product and then took a plaque test to see how much plaque was left. She used Crest, Colgate, Close-up, and water. what is the independent variablewhat is the dependent variablewhat is the control variable

Independent: toothpaste brand

Dependent: amount of plaque left

Control: Water

Constants: amount of toothpaste, kind of toothbrush, how long the toothbrushing took.

Explanation:

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.

using the scientific method.