4) [10 points] Assume that the U.S. real GDP in 2010 was $13,000 billion (in year-1990 dollars). In 1990, real GDP was $8,000 billion (in year-1990 dollars). a) Use the compound growth formula to compute the average annual growth rate of real GDP from 1990 and 2010. Answer: b) If the $13,000 billion in 2005 was actually in year 2010 dollars and the price index that year was 150 (with the index in 1990, the base year, equal to 100), what was the actual average annual growth rate of real GDP between 1990 and 2010