Mortgage rates inched lower Friday as preliminary fourth quarter GDP estimates fell short of expectations. The economy grew at an annual rate of 2.6% last quarter, below the consensus forecast of 3.2%. For all of 2014, GDP increased by 2.4%. Among the various components of the report, consumer spending was a bright spot, rising at the fastest pace in almost nine years. Business investment was weak, however, as were foreign exports. Separately, the Chicago Purchasing Managers Index rose to 59.4, beating expectations. Consumer Sentiment fell slightly to 98.1. A reading of 98.2 had been expected. No other key data will be released today.