Japan's currency intervention last week cost 2.84 trillion yen ($19 billion), the largest-ever amount spent to stem the yen's sharp slide against the U.S. dollar, Finance Ministry data showed Friday.The yen-buying, dollar-selling operation, Japan's first since 1998, was carried out on Sept. 22, shortly after the Japanese currency plunged past the psychologically-important 145 mark amid prospects that the monetary policies of Japan and the United States would further diverge.Friday's data covers the period between Aug. 30 and Sept. 28, and no daily breakdown was disclosed. Previously, 2.62 t…READ FULL ARTICLE