KJ Painting is estimating the time it will take to paint the 8,600 sq ft of walls of a school gym. Kay can paint 420 sq ft in 4 hours. Jay can paint 540 sq ft in 5.5 hours. They are going to add 15% to the initial square footage time estimate for the extra time required for painting the tall walls of the gym. How much time do they estimate to the nearest quarter hour?