4. 16.12 How much can a dollar buy? The buying power of a dollar changes over time. The Bureau of Labor Statistics measures the cost of a market basket" of goods and services to compile its Consumer Price Index (CPI). If the CPI is 120, goods and services that cost $100 in the base period now cost $120. Here are the average values of the CPI for the years between 1970 and 2018. The base period is the years 1982 to 1984. Year CPI Year CPI Year CPI 1970 38.8 1990 130.7 2010 218.1 1972 41.8 1992 140.3 2011 224.9 1974 49.3 1994 148.2 2012 229.6 1976 56.9 1996 156.9 2013 233.0 1978 65.2 1998 163.0 2014 236.7 1980 82.4 2000 172.2 2016 240.0 1982 96.5 2002 179.9 2018 251.0 1984 103.9 2004 188.9 1986 109.6 2006 201.6 1988 118.3 2008 215.3 a. Make a graph that shows how the CPI has changed over time. b. What was the overall trend in prices during this period? Were there any years in which this trend was reversed? c. In which years were prices rising fastest, in terms of percentage increase? In what period were they rising slowest? 4. 16.12 How much can a dollar buy? The buying power of a dollar changes over time. The Bureau of Labor Statistics measures the cost of a market basket" of goods and services to compile its Consumer Price Index (CPI). If the CPI is 120, goods and services that cost $100 in the base period now cost $120. Here are the average values of the CPI for the years between 1970 and 2018. The base period is the years 1982 to 1984. Year CPI Year CPI Year CPI 1970 38.8 1990 130.7 2010 218.1 1972 41.8 1992 140.3 2011 224.9 1974 49.3 1994 148.2 2012 229.6 1976 56.9 1996 156.9 2013 233.0 1978 65.2 1998 163.0 2014 236.7 1980 82.4 2000 172.2 2016 240.0 1982 96.5 2002 179.9 2018 251.0 1984 103.9 2004 188.9 1986 109.6 2006 201.6 1988 118.3 2008 215.3 a. Make a graph that shows how the CPI has changed over time. b. What was the overall trend in prices during this period? Were there any years in which this trend was reversed? c. In which years were prices rising fastest, in terms of percentage increase? In what period were they rising slowest