Select all true statements. Countries with a high real per capita GDP tend to also have a high human development index (HDI) on average. Countries with high real per capita GDP tend to have a population with higher level of education and higher life expectancy on average. We use real per capita GDP to measure the standard of living because money makes you happy. For a country, high real per capita GDP implies a high standard of living. We use real per capita GDP to measure the standard of living because variables that determine welfare seem to be positively correlated with it. We use real per capita GDP to measure the standard of living because consumption makes you happy. A higher human development index (HDI) implies a higher real per capita GDP