The document outlines a task to calculate the Consumer Price Index (CPI) for the years 1971, 1981, 1992, and 2012 using specified data, with 1981 as the base year. It also instructs on calculating the percentage changes in nominal and real GDP from 1971 to 2012 and requires an explanation of the differences between these two types of percentage changes. The key formula provided is CPI = (current year expenditure * 100) / (base year expenditure).