A research group interested in understanding the effect of listening to classical
music on learning mathematics conducted a study. One hundred students were
randomly assigned to one of two groups. The first group listened to classical music
as they learned a new lesson. The second group learned the same lesson with no
music playing. Both groups were tested on the new material to determine how
much they learned. The results for the two groups were compared. What kind of
study is this? (2 points)