3). Some Data on Life Expectancy, Infant Mortality, GNP and More! (20 points) a). You are thinking about explaining the variation in LExpM by country with a regression using some of the other variables below. What might you learn from this correlation matrix about creating your best model? Roughly speaking, how do these correlation levels compare to R2. (10 points) BirthRt DeathRt InfMort GNP LEXPM LEXPF BirthRt DeathRt 0.504858 InMort 0.856586 0.676806 GNP -0.62905 -0.30084 0.60175 LEXPM -0.86534 -0.7542 0.93427 0.640653 LExpF -0.89384 -0.71485 0.95354 0.648197 0.981938 BirthRt Live birth rate per 1000 population DeathRt Death rate per 1000 population InfMort Infant deaths per 1000 population under 1 year LEXPM Life expectancy at births for males LExpF Life expectancy at births for females GNP Gross National Product, per capita, US$ The residual plot below is from a regression looking at a regression attempting to explain Male Life Expectancy differences by country with GNP differences by country. b). Very briefly discuss what you look for in residual plots. Discuss what you might see in this residual plot. (10 points) GNP Residual Plot 20 Residuals 10000 20000 30000 40900 120 -40 GNP