By MATT OTT WASHINGTON (AP) — Average long-term U.S. mortgage rates jumped back up ahead of next week's Federal Reserve meeting where it's expected to announce another big increase to its main borrowing rate. Mortgage buyer Freddie Mac reported Thursday that the 30-year rate jumped to 5.23% this week from 5.09% last week. A year ago at this time, the average rate was 2.96%. Until April, the average