WASHINGTON — The number of people seeking unemployment benefits rose slightly last week, but remained at historically low levels that signal a strengthening job market.

Weekly applications increased 3,000 to a seasonally adjusted 287,000, the Labor Department said today. The four-week average, a less volatile measure, declined 250 to 281,000, the lowest level in more than 14 years.

Applications are a proxy for layoffs and have fallen 20 percent in the past year. At the same time, hiring has picked up. Employers are adding jobs this year at the healthiest pace in eight years.

That is contributing to faster growth: The economy expanded at a solid annual rate of 3.5 percent in the July-September quarter, according to a separate government report today. More business investment and exports, as well as a burst of government spending on defense, drove the increase.

Employers have added an average of 227,000 jobs a month this year, up from an average of 194,000 last year.

SALT LAKE CITY — A Utah couple and their three children found dead in their home last month were likely poisoned, their bodies found together in a locked room with cups next to each of them, and empty bottles of methadone and nighttime cold medicine in a trash can.Police aren't saying who killed the family or whether one of the parents might have been involved. Toxicology results have not determined an exact cause of death, but search warrants obtained Wednesday say the family was likely poisoned.Benjamin and Kristi Strack were in bed, with children ages 11 through 14 lying around them, tucked in bedding up to their necks, according to the search warrants. Kristi Strack had a red liquid coming out of her mouth.Some of the bodies looked to have been positioned after they died Sept. 27. They were found by the couple's older son and Kristi Strack's mother.