This example uses the Spring Data.jmp sample data table. Four different brands of springs were tested to see what weight is required to extend a spring 0.10 inches. Six springs of each brand were tested. The data was checked for normality, since the ANOMV test is not robust to non-normality. Examine the brands to determine whether the variability is significantly different between brands.
1.
Select Help > Sample Data Library and open Spring Data.jmp.
2.
Select Analyze > Fit Y by X.
3.
Select Weight and click Y, Response.
4.
Select Brand and click X, Factor.
5.
6.
From the red triangle menu, select Analysis of Means Methods > ANOM for Variances.
Figure 5.63 Example of Analysis of Means for Variances Chart
From Figure 5.63, notice that the standard deviation for Brand 2 exceeds the lower decision limit. Therefore, Brand 2 has significantly lower variance than the other brands.

Help created on 7/12/2018