Read the study and determine whether or not each description applies.

Mariah is testing whether or not loud music causes people to drive more recklessly. Mariah flips a coin for each participant and places everyone who got heads into one group and everyone who got tails into the other. All participants complete a driving simulator course that measures their speeds and number of mistakes. Mariah then has one group listen to a rock song at a very loud volume, and the other at a lower volume. After listening to the song, participants once again complete the driving simulator course.