4,75%, why?

"Today's action is intended to help forestall some of the adverse effects on the broader economy that might otherwise arise from the disruptions in financial markets", the Federal Open Market Committee said in a statement after meeting today in Washington. The central bank will "act as needed to foster price stability and sustainable economic growth."
"Economic growth was moderate during the first half of the year, but the tightening of credit conditions has the potential to intensify the housing correction, and to restrain economic growth more generally"