Consider an imaginary economy that has been growing at a rate of 6% per year. government economists have proposed a number of policies to increase the growth rate but first need to convince the president that the policies will pay off. to do so, they want to present a comparison of the number of years it will take for the economy to double, depending on the growth rate. using the rule of 70, determine the number of years it will take the economy to double at each growth rate.