The population of Middle-earth (in billions) is given by , where is the time in years since 2000. What is the doubling time for the population of Middle-earth? (Round to two decimal places).
years
We want to know when the population will be double of billion, which is billion. That is, we want to solve the equation
for .
Note that you will need to use logarithms in order to do this. We suggest you use natural or common logarithm.