20. Callahan (2009) conducted a study to evaluate the effectiveness of physical exercise programs for individuals with chronic arthritis. Participants with doctor-diagnosed arthritis either received a Tai Chi course immediately or were placed in a control group to begin the course 2 weeks later. At the end of the 8-week period, self-reports of pain were obtained for both groups. Data similar to the results obtained in the study are shown in the following table.
Self-Reported Level of Pain Mean SE
Tai Chi course 3.7 1.2
No Tai Chi course 7.6 1.7
a. Construct a bar graph that incorporates all of the information in the table.
b. Looking at your graph, do you think that participation in the Tai Chi course reduces arthritis pain?