AlQa'dah 20, 1436, September 04, 2015, SPA -- U.S. stocks closed more than 1 percent lower Friday ahead of a three-day holiday weekend as uncertainty about the timing of a U.S. interest-rate increase and Chinese economic growth continued to concern investors. The Dow Jones industrial average fell 272.38, or 1.7 percent, to 16,102.38. The broader Standard & Poor's 500 index fell 29.90, or 1.5 percent, to 1,921.23. The technology-heavy Nasdaq composite index fell 49.58, or 1.05 percent, to 4,683.92.