What percentage of the variation in state average test scores is explained by these two variables? Which variable(s) are significant? (b) Does Minitab flag any high leverage values? Do any states stand out with respect to Cook"s Di or DFITS? (c) Now let"s explore including expend (total state expenditure on secondary schools) in the model. Use a fitted line plot to create an added variable plot to evaluate the effects of expend after accounting for the self-selection of students taking the SAT. What do you learn? (d) Then also run the regression of the corresponding residuals and examine the residuals and case influence statistics, do any states stand out? (e) Any justification for removing this state from the analysis? Statistically Significant Outlier? (f) The residuals for Alaska in the original regression is above 50. Explain why it is not generally informative to judge the unusualness of an observation purely by the magnitude of its residual?