The geometric mean is often used in business and economics for finding average rates of change, average rates of growth, or average ratios. Given n values (all positive), the geometric mean is the nth root of their product. The average growth factor for money compounded at annual interest rates of 35%, 47%, 41%, and 40% can be found by computing the geometric mean of 1.35, 1.47, 1.41, and 1.4. Find that average growth factor.