The Current Population Survey (CPS) is a survey conducted by the U.S. Bureau of the Census for the Bureau of Labor Statistics. It provides a comprehensive body of data on the labor force, unemployment, wealth, poverty, and so on. The data can be found online at www.census.gov/cps/. Data from the 2012 CPS examined about 68,000 households, each consisting of at least one related person under the age of 18. The report indicated that 18% of white households, 37.5% of black households, and 13.4% of Asian households had annual incomes below the poverty line. Based on these results, the study authors concluded that the percentage of all such black households with annual incomes below the poverty line is between 35.6% and 39.4%. Specify the aspect of this study that pertains to

(a) Description 

(b) Inference.