What you must do is evaluate the function for the given conditions and thus be able to find the constants A and k 25 = Ae ^ k (2005) 31 = Ae ^ k2010 We then have two equations with two unknowns. Solving. 25/31 = e ^ k (2005-2010) Ln (25/31) = k (2005-2010) k = Ln (25/31) / (2005-2010) = 0.043 Substituting k in any of the equations: 25 = Ae ^ (0.043 * (2005)) Clearing A A = 25 / (e ^ (0.043 * (2005))) = 9.02E-37 Then, by 2020 P = (9.02E-37) e ^ (0.043 * (2020)) = 48 million answer the population for 2020 will be 48 million