Again, X and β are redefined, so that Zn is eliminated, and the computations repeated. This analysis gives the results in Table 5.5 the partial sum of squares for pH increases dramatically when Zn is dropped from the modal, from 1.9 million to 11.5 million. This is due to the strong correlation between pH and Zn (r= -72). When
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two independent variables are highly correlated, either positively or negatively, much
of the predictive information contained in either can be usurped by the other. Thus,
a