Photo An investor at a securities company in Beijing. Investors have been on edge in recent weeks amid renewed turmoil in China’s stock markets and currency exchange rate. Credit Wang Zhao/Agence France-Presse — Getty Images HONG KONG — China’s growth slowed further last year, adding to the troubling economic picture that is unsettling investors around the world. The Chinese economy grew at a 6.8 percent pace in the fourth quarter, according to data released on Tuesday. It was the lowest quarterly expansion since the global financial crisis in 2009. Uncertainty about the Chinese economy — and whether the government can manage a slowdown — has been weighing heavily on global markets in recent weeks. Investors, in part, are trying to determine if China’s slump will spread, dragging down the rest of the world. The latest data is not likely to reassure investors that all is well in China, the […]