In the context of the United Nations Human Development Report, completed years of educational attainment refer to: 1)absolute years of schooling. 2)expected years of schooling. 3)mean years of schooling. 4)relative years of schooling.__________ measures the extent to which the distribution of income (or consumption expenditures) among individuals or households within an economy deviates from a perfectly equal distribution. 1)Pigou's equation 2)The Pearson coefficient 3)Marshall's equation 4)The Gini coefficient