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.
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Select Analyze > Fit Y by X.
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Click OK.
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From the red triangle menu, select Analysis of Means Methods > ANOM for Variances.
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From the red triangle menu next to Analysis of Means for Variances, select Show Summary Report.
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From Example of Analysis of Means for Variances Chart, notice that the standard deviation for Brand 2 exceeds the lower decision limit. Therefore, Brand 2 has significantly lower variance than the other brands.