The compound interest formula is given by A P 1 5 where A is the accumulated amount after an initial investment of P dollars is invested for t years at annual interest rate r compounded in times per year Use the formula above to determine how long it will take an initial investment of 26 000 to quadruple if the account earns 6 interest per year compounded monthly Round the solution to two decimal places The account balance will quadruple after Use the formula above to determine how long it will take an initial investment of 26 000 to quadruple if the account earns 12 interest per year compounded monthly Round the solution to two decimal places The account balance will quadruple after years years