The development economist has expanded her analysis. Apart from annual population growth (%), per capita GDP (PPP current international thousand dollars), and subjective wellbeing (SWB), she has added the following variables to the file Countries electric power consumption (per capita \(\mathrm{kWh}\) ), crude death rate (per 1,000 people), life expectancy at birth (years), and ecological footprint (global hectare). Develop the most appropriate multiple regression model to predict a country's SWB. Be sure to include a thorough residual analysis. Provide a detailed explanation of the results.