By Stephen Culp NEW YORK (Reuters) – A robust, broad-based rally sent Wall Street to a sharply higher close on Friday as encouraging economic data and a rosier earnings outlook boosted investor risk appetite ahead of next week’s much-anticipated two-day policy meeting of the Federal Reserve. All major U.S. indexes ended the session up more than 2%, with the S&P and the Nasdaq notching their second straight weekly gains. The blue-chip Dow posted its fourth consecutive Friday-to-Friday advance and its biggest weekly percentage gain since May. “This has been one of the best months (so far) in the…