Hallam, Price, and Katsarou (2002) investigated the influence of background noise on classroom
performance for children aged 10 to 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 n 18
students who listen to calming music each day while
working on arithmetic problems. A second class
of n 18 serves as a control group with no music.
Accuracy scores are measured for each child and
the average for students in the music condition is
M 86.4 with SS 1550 compared to an average of
M 78.8 with SS 1204 for students in the nomusic condition.
a. Is there a significant difference between the two
music conditions? Use a two-tailed test with .05.
b. Compute the 90% confidence interval for the
population mean difference.
c. Write a sentence demonstrating how the results
from the hypothesis test and the confidence interval
would appear in a research report.