Piper invested $7,400 in a Certificate of Deposit, $4,980 in a corporate bond, $5,100 in a common stock, and $6,350 in a preferred stock, The COD has a rate of return of 3.4%; the corporate bond is 5.8%; the common stock's rate of return is -1.9%; and the preferred stock has a rate of return of 4.6%. What is Piper's weighted mean rate of return? (2 points)