(Solving for n with non-annual periods)Approximately how many years would it take for an investment to grow fivefold if it were invested at 15 percent compounded monthly? Assume that you invest $1 Today

If you invest $1 at 15 percent compounded monthly, about how many years would it take for your investment to grow fivefold to $5? (Hint: Remember to convert your calculator solution to years.)

____ (Round to one decimal place.)