WASHINGTON — Rates on 30-year mortgages fell for a fifth consecutive week as both sales of both existing and new homes in July declined, confirming a cooling housing market.

The mortgage company Freddie Mac said yesterday that 30-year fixed-rate mortgages fell to 6.48 percent this week, down from 6.52 percent last week.

That was the lowest level for 30-year mortgages since they averaged 6.43 percent the week of April 6.

Mortgages had risen since then, hitting a more than four-year high of 6.80 percent the week of July 20 before falling in the past five weeks.

Analysts view the rollback in rates as further evidence that the economy is slowing, which should ease inflation pressures.

Rates on 15-year fixed-rate mortgages, a popular choice for refinancing, averaged 6.18 percent this week, down from 6.20 percent last week.

For one-year adjustable-rate mortgages, rates dipped to 5.60 percent from 5.65 percent last week.

Rates on five-year adjustable-rate mortgages declined to 6.14 percent this week from 6.18 percent last week.