A mathematical approximatlon called the rule of 70 tells us how long It will take for something to double in size lflt grows at a constant rate. The doubllng time ls approximately equal to the number 70 divlded by the percentage rate of growth. Thus. lf Panama 5 real GDP per person ls growing at 7 percent per year. It wIII take about 10 years (= 70/7) to double. Apply the rule of 70 to solve the following problem: Suppose that real GDP per person In Panama In 2017 was about $13,000 per person, while it was about $52,000 per person in the United States. If real GDP per person In Panama grows at the rate of 4 percent per year, about how long will it take Panama 5 real GDP pet 92am to reach the level that the United States was at in 2017? (Hint How many times would Panama's 2017 real GDP per person A ' hornets double to reach the United States' 2017 real GDP per person?) Wm: Enter your answer as a whole number. r"n._