Example 2.1 with Pie Chart - Graphing and Summarizing Qualitative Data
A group of cardiac physicians in southwest Florida have been studying a new drug designed to reduce blood loss in coronary artery bypass operations. Blood loss data for 114 coronary artery bypass patients (some who received a dosage of the drug and others who did not) are saved in the BLOODLOSS file. Although the drug shows promise in reducing blood loss, the physicians are concerned about possible side effects and complications. So their data set includes not only the qualitative variable, DRUG, which indicates whether or not the patient received the drug, but also the qualitative variable, COMP, which specifies the type (if any) of complication experienced by the patient. The four values of COMP recorded by the physicians are (1) redo surgery, (2) post- op infection, (3) both, or (4) none. Figure 2.5, generated using SPSS, shows summary tables for the two qualitative variables, DRUG and COMP. Interpret the results. Interpret the Minitab output shown in Figure 2.6 and the SPSS output shown in Figure 2.7. This tutorial will demonstrate how to use Minitab to reproduce Figures 2.5, 2.6 and 2.7 on page 36 of the textbook. Steps one through 8 will produce tables similar to those of Figure 2.5 on page 36 of in the text After loading the minitab worksheet BLOODLOSS.MTW: 1. Begin by clicking on Stat. 2. Next, click on Tables. 3. Then click on Tally Individual Variables. 4. Double-click C2 DRUG. 5. Double-click C3 COMP. 6. Click the Percents button. 7. Click the Cumulative percents button. 8. Click the OK button.

As you can see the tables generated by Minitab are slightly different than those of Figure 2.5. This is because a different statistical package was used to produce the tables in Figure 2.5 of the text. The minitab tables are side by side rather than one above the other, there is no Valid Percent Column and the percentages are carried out to two decimal places, rather than rounded to one decimal place. Click the continue button to continue the tutorial. Steps nine through 17 will reproduce Figure 2.6 found on page 36 in the text 9. Click on Graph. 10. Click on Bar Chart. 11. Click the OK button. 12. Double-click C3 COMP item. 13. Click the Multiple Graphs... button. 14. Click the By Variables tab. 15. Double-click C2 DRUG.

Example 2.1 with Pie Chart - Graphing and Summarizing Qualitative Data
16. Click the OK button. 17. Click the OK button.

As can be seen, the minitab graph matches exactly Figure 2.6 in the text. This is because Minitab was also used to produce the figure in the text. Click the continue button to continue the tutorial. Steps 18 through 30 will produce two tables containing the information shown in Figure 2.7 on page 36 in the text. 18. Click on Data. 19. Click on Unstack Columns. 20. Double-click C3 COMP. 21. Click in the Using subscripts in: text box. 22. Double-click C2 DRUG. 23. Click the After last column in use radio button. 24. Click the OK button. 25. Click on Stat. 26. Click on Tables. 27. Click on Tally Individual Variables. 28. Double-click C4 COMP_NO. 29. Double-click C5 COMP_YES. 30. After checking the boxes for Counts, Percents, and Cumulative Percents, click the OK button.

Again the tables generated by Minitab are slightly different than those of Figure 2.7. This is because, as with Figure 2.5, a different statistical package was used to produce the tables in Figure 2.7 of the text. The minitab tables are side by side rather than one above the other, there is no Valid Percent Column and the percentages are carried out to two decimal places, rather than rounded to one decimal place. Click the continue button to continue the tutorial. Steps 31 through 44 will produce pie chart equivalents of Figure 2.6 on page 36 in the text 31. Click on Graph. 32. Click on Pie Chart. 33. Click in the Categorical variables textbox and then double-click COMP. 34. Click the Multple Graphs button. 35. Click the By Variables tab. 36. Click in the By variables with groups on the same graph textbox and then double-click DRUG. 37. Click on OK. 38. Click the Labels Button.

Example 2.1 with Pie Chart - Graphing and Summarizing Qualitative Data
39. 40. 41. 42. 43. Click the Slice Labels tab. Check the Percent checkbox. Check the Draw a line from label to slice checkbox. Click on OK. Click on OK.

To view a click summary for this tutorial, click on Continue. To see the second part of the click summary, click on Continue. To see the last part of the click summary, click on Continue. To end this tutorial, click on End.