8. Let's say an aviation researcher conducted a one-tailed test of the hypothesis that avia- tion maintenance technicians (AMTS) who listen to music during their shift will be more productive than AMTS who do not listen to music during their shift. Using a research- er-developed measure of productivity where 0 indicates "not productive" and 10 indi- cates "highly productive," the researcher reported that the mean score for the sample of 40 AMTs who listened to music during their shift was 3, the mean score for the sam- ple of 50 AMTS who did not listen to music during their shift was 6, and the standard error of the difference in the means was 0.5. What should you conclude from this study?

a. Listening to music during their shift caused AMTS to be less productive.

b. There was no significant difference in productivity between AMTs who listened to or did not listen to music during their shift.

c. AMTS who listened to music during their shift had significantly lower productiv- ity scores than AMTs who did not listen to music during their shift.

d. AMTS who listened to music during their shift had significantly higher productiv- ity than AMTs who did not listen to music during their shift.