Sara invested 3,400 six years ago. Today, her investment is worth4,200. Which formula will correctly compute her rate of return?
1) Rate of return = (Final value - Initial value) / Initial value
2) Rate of return = (Initial value - Final value) / Initial value
3) Rate of return = (Final value - Initial value) / Final value
4) Rate of return = (Initial value - Final value) / Final value