With the Federal Reserve widely expected Wednesday to reduce its key interest rate by a quarter-point to about 4.1%, economists and Wall Street investors will be looking for signals about next steps: How deeply might the Fed cut in the next few months?There are typically two different approaches the central bank takes to lowering borrowing costs: Either a measured pace that reflects a modest adjustment to its key rate, or a much more rapid set of cuts as the economy deteriorates in an often-doomed effort to ...