Hallam, Price, and Katsarou (2002) investigated the influence of background noise on classroom performance for children aged 10-12. In one part of the study, calming music led to better performance on an arithmetic task compared to a no-music condition. Suppose that a researcher selects one class of 18 students who listen to calming music each day, while a second class of 18 students serves as a control group with no music. Accuracy scores are measured for each child. Which hypothesis test would be appropriate for this example