1.19 Table 1.8 gives the index of industrial production for selected countries (U.S. Census Bureau, Statistical Abstract of the United States, 2000).

a Construct appropriate plots to summarize the index of industrial production for the years 1990 and 1998. How would you describe these distributions?

b Calculate the difference between indices for 1990 and 1998. Summarize these differences using an appropriate plot. Comment on the result.