Mortgage rates moved up slightly heading into the end of the year, according to the latest data released yesterday by Freddie Mac, the Washington Post reported today. The 30-year fixed-rate average nudged up to 4.48 percent, and it was 4.47 percent a week ago and 3.35 percent a year ago. Since spiking to 4.58 percent in late August, the 30-year fixed rate has bounced between 4.57 and 4.1 percent. The 15-year fixed-rate average ticked up to 3.52 percent, and was 3.51 percent a week ago and 2.65 percent a year ago. Before rising above 3.5 percent last week, the 15-year fixed rate had remained below that mark since late September.