A researcher is investigating the effect of background noise on classroom performance for children aged 10 to 12. One class ofN= 16 students who listens to calming music each day while working on arithmetic problems is chosen as the experimental group (group 1). Another class of N = 16 students serves as a control group with no music (group 2). Accuracy scores are measured for each child, and the average for students in the music condition is X= 86.75 withSS= 1250. For the no-music condition, the average isX= 78.8, withSS= 1180.

B) Compute Cohen'sd to estimate the size of the described effect (using the small, medium or large designation used in class).

Asd= , there was a effect of background noise on accuracy scores.