Example of the Cochran Armitage Trend Test
Use the Contingency platform to investigate whether there is a relationship between the proportion of males and females that buy different sizes of cars.
1. Select Help > Sample Data Folder and open Car Poll.jmp.
For the purposes of this test, change size to an ordinal variable:
2. In the Columns panel, right-click the icon next to size and select Ordinal.
3. Select Analyze > Fit Y by X.
4. Select sex and click Y, Response.
5. Select size and click X, Factor.
6. Click OK.
7. Click the Contingency Analysis red triangle menu and select Cochran Armitage Trend Test.
Figure 7.16 Example of the Cochran Armitage Trend Test Report
The two-sided p-value (0.7094) is large. From this, you cannot conclude that there is a relationship in the proportion of male and females that purchase different sizes of cars.