You'd like to purchase a new car after you graduate and start working. The car that you would really like costs $31,000. You are currently earning a rate of 5.88% in an investment account. If you currently have $15,500 and expect to continue to earn 5.88% annually, how long will it be until you have enough to purchase the car (assuming the car still sells for that amount)? (Use the Rule of 72 for calculation) (Round answer to 2 decimol ploces, es. 5. 5.75.)