(Solving for n with non-annual periods) Approximately how many years would it take for an investment to grow sixfold if it were invested at 9 percent compounded monthly? Assume that you invest $1 today. If you invest $1 at 9 percent compounded monthly, about how many years would it take for your investment to grow sixfold to $6 ? (Hint: Remember to convert your calculator solution to years.) years (Round to one decimal place.)