Use the formula t = ln 2/k that gives the tine for a population with a growth rate k to double. The growth model A = 5.1 e^0.00t describes a country's population, A, in millions, t years after 2010. a. What is that country's growth rate? b. How long will it take that country to double its population? a. What is the country's growth rate? The country's growth rate is %. (Round to the nearest whole number as needed.) b. How long will it take the country to double its population?