A data scientist uses PROC HPREG to fit a polynomial regression with terms up to degree 3. How should the cubic term for variable 'X' be specified in the MODEL statement?
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Short Explanation and Infographic
Here's the deal — c is correct because in PROC HPREG (and PROC REG), polynomial terms are specified by creating variables or using the power operator . X2 specifies X squared and X**3 specifies X cubed in the MODEL statement.
Full explanation below image
Full Explanation
C is correct because in PROC HPREG (and PROC REG), polynomial terms are specified by creating variables or using the power operator . X2 specifies X squared and X**3 specifies X cubed in the MODEL statement. A uses multiplication notation which SAS interprets as interaction terms between separate variables named X, not polynomial powers of the same variable. B uses bar notation which generates factorial crossing interactions, not polynomial terms. D uses a POLY() function that does not exist in SAS PROC HPREG.