Wall Street ends flat in quiet end to dramatic week

By Noel Randewich Aug 28 (Reuters) - Wall Street ended a tumultuous week with a flat close on Friday as investors shrugged off concerns that a September rate rise was more likely than some investors expected. Shares traded lower earlier in the session after Fed Vice Chairman Stanley Fischer told CNBC the Fed had not yet decided whether to raise interest rates in September. After several volatile sessions that at one point pushed the S&P 500 to its lowest level since October 2014, the three m