Mortgage rates decreased this week, according to Bankrate's latest survey of large lenders.

The benchmark 30-year fixed-rate mortgage went down 6 basis points to 4.27 percent. The benchmark 15-year fixed-rate mortgage moved down 4 basis points to 3.49 percent.

A basis point is one-hundredth of 1 percent.

The typical 30-year fixed-rate jumbo declined to 4.27 percent. For the purposes of Bankrate's survey, a jumbo mortgage is a loan that is at least $650,000.

The average 5/1 adjustable-rate mortgage went down 3 basis points to 3.46 percent. With a 5/1 ARM, the rate is fixed for five years and adjusted annually thereafter.