For the data for 21 nations in the UN2 data file at the text website that are not missing observations on literacy, Table 14.10 shows various diagnostics from fitting the multiple regression model relating fertility (mean number of births per woman) to literacy rate and women’s economic activity.

(a) Study the studentized residuals. Are there any apparent outliers?

(b) Which, if any, observations have relatively large leverage values?

(c) Based on the answers in

(a) and (b), does it seem as if any observations may be especially influential? Explain.

(d) Study the DFFIT values. Identify an observation that may have a strong influence on the fitted values.

(e) Study the DFBETA values. Identify an observation that is influential for the literacy estimate but not for the economic activity estimate.