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)