Beijing: The central parity rate of the Chinese yuan, weakened to 294 basis points on Monday to 6.5784 against the US dollar, the lowest since February 2011. According to the China Foreign Exchange Trading System, the fall came after US Federal Reserve Chair Janet Yellen said at Harvard University on Friday that an interest rate hike in the next few months would probably be appropriate if economic data improves, Xinhua news agency reported. Her comments boosted the US dollar against other major currencies. In China's spot foreign exchange market, the yuan is allowed to rise or fall by 2 percent from the central parity rate each trading day. The central parity rate of the yuan against the US dollar is based on a weighted average of prices offered by market makers before the opening of the interbank market each business day.