Your parents will retire in 23 years. They currently have $290,000 saved, and they think they will need $900,000 at retirement. What annual interest rate must they earn to reach their goal, assuming...

Your parents will retire in 23 years. They currently have $290,000 saved, and they think they will need $900,000 at retirement. What annual interest rate must they earn to reach their goal, assuming they don't save any additional funds? Round your answer to two decimal places.