Major averages followed the lead of China stocks Friday, ending the week with a thud. So did crude oil. The Nasdaq closed in the upper half of its range but still lost 2.7%, weighed down by weakness in chip stocks. The Dow Jones industrial average dropped 2.4% and the S&P 500 gave up 2.2%. For the week, the Nasdaq shed 3.3%; the Dow and S&P 500 lost 2.2% each. Coal, oil and gas, and chip stocks lagged. REITs outperformed again.