The researcher in exercise 2 decides to conduct the same study using a withinparticipants design to control for differences in cognitive ability. He selects a random sample of subjects and has them study different material of equal difficulty in both the music and no-music conditions. The study is completely counterbalanced to control for order effects. The data appear next. As before, they are measured on a interval-ratio scale and are normally distrusted; he believes that studying under quiet conditions will lead to better performance.
Music No Music
7 7
6 8
5 7
6 7
8 9
8 8
a. What statistical test should be used to analyze these data?
b. Identify Ho and Ha for this study
c. Conduct the appropriate analysis.
d. Should Ho be rejected? What should the researcher conclude?
e. If significant, compute and interpret the effect size.
f. If significant, draw a graph representing the data.
g. Determine the 95% confidence interval.