Financial advising  It often becomes tempting to  add a large collection of variables to a regression, ...

Financial advising  It often becomes tempting to  add a large collection of variables to a regression,  hoping to let regression “sort out” which variables are important rather than think about why each might  matter. Beginning with the model shown in Table 4, add the ten variables that measure population in the  ZIP Code of the business location to the model (Population of ZIP Code through Female Population).

(a)  What happens when these are added to the  model?

(b)  How should these variables be added more  sensibly? Does doing so produce a statistically  significant improvement in the fit? Explain.