Sally invests $5000 in an account earning 8% interest, compounded continuously. After how many years will she double her investment? [Use the formla A = Pert and round answer to the nearest tenth.
8.7 years is correct. Plug in 10000 for A, divide both sides by 500, then take the natural logarithm of both sides to get ln(2) = .08t. Divide by .08 to get the answer.