- The Consumer Price Index (CPI) measures the average price of a number items that the typical consumer frequently purchases. Changes in the CPI are often used to estimate inflation from year to year. Suppose the average price of goods that make up the CPI is $102.24 in US dollars. The average price of the same basket of goods in Australia is 135.50 Australian dollars (AUD). If absolute purchasing power parity (PPP) were to hold across these countries, what would current the exchange rate be, in terms of AUD per US dollar