Federal Reserve Chairman Jerome Powell signaled the central bank was likely to raise interest rates by a half percentage point at its meeting next month and indicated similar rate rises could be warranted after that to lower inflation. A rate increase in May, following the Fed’s decision to lift rates from near zero by a quarter percentage point last month, would mark the first time since 2006 that the central bank increased its policy rate at back-to-back meetings. A half-point increase would be the first such move since 2000.