The covariance analysis of the phosphorus study in Section 9.8.3 assumed a common regression of forage yield on soil phosphorus. Use a general linear analysis program (such as PROC GLM in SAS) to test...

The covariance analysis of the phosphorus study in Section 9.8.3 assumed a common regression of forage yield on soil phosphorus. Use a general linear analysis program (such as PROC GLM in SAS) to test the homogeneity of regressions over the 14 treatment groups.