The economic dynamism, which is the index of productive growth in dollars for countries that are designated by the world bank as middle-income are in table #7. 3. 8 ("socr data 2008," 2013). Countries that are considered high-income have a mean economic dynamism of 60. 29. Do the data show that the mean economic dynamism of middle-income countries is less than the mean for high-income countries? test at the 5% level.