1. Select Help > Sample Data Library and open Big Class.jmp.
2. Select Analyze > Fit Y by X.
3. Select weight and click Y, Response.
4. Select age and click X, Factor.
5. Click OK.
6. Click the red triangle next to Oneway Analysis of weight By age and select Compare Means > With Control, Dunnett’s.
7. Select the group to use as the control group. In this example, select age 12.
Alternatively, click a row to highlight it in the scatterplot before selecting the Compare Means > With Control, Dunnett’s option. The test uses the selected row as the control group.
8. Click OK.
Figure 6.21 Example of With Control, Dunnett’s Comparison Circles
Using the comparison circles, you can conclude that level 17 is the only level that is significantly different from the control level of 12.