A researcher wants to evaluate the learning ability of college students with various background sounds during learning. She randomly divides 21 participants into three groups. All students study a passage of text for 30 minutes. Those in group 1 study with background sound at a constant volume in the background. Those in group 2 study with noise that changes volume randomly. Those in group 3 study with no sound at all. After studying, all students take a 10-point multiple choice test about the material. Their scores follow:

(40 points)

Constant sound

Random sound

No sound

7

5

5

4

5

6

6

3

7

8

4

9

6

4

8

6

6

7

9

2

6

A. What statistical test should you perform? Be as specific as possible.(5 points)

B. What is the overall result of the statistical analysis (hint: think "first sentence")? Include statistical notation.(6 points)

C. Is the constant sound group significantly different from the random sound group? Describe the relationship and include statistical notation.(6 points)

D. Is the constant sound group significantly different from the no sound group? Describe the relationship and include statistical notation.(6 points)

E. Is the random sound group significantly different from the no sound group? Describe the relationship and include statistical notation.(6 points)

F. Write a sentence in "plain English" that describes the results of the experiment.(8 points)

G. Graph your results (include axis titles, chart title, means and SEM error bars).(3 points)