Rick decided he was tired of being a poor college student when he visited a local electronics store and experienced its finest home theatre system. He determined that he would invest today a portion of the remaining money he earned last summer cleaning animal cages at the veterinary clinic. He plans to invest the money into an international mutual fund for 2.5 years and expects to earn an average annual rate of return of 15%. If Rick wants to have $5,000 in the account at the end of this time, how much must he invest today?