The Dow Jones industrial average closed at a record high Tuesday after reports on auto sales and factory orders provided the latest evidence that the U.S. economy is strengthening. Traders plowed money back into European stocks as the financial situation in Cyprus appeared to stabilize.The Dow closed up 89.16 points, or 0.6 percent, at 14,662.01. It had risen as high as 14,684 in the late morning.Health insurers powered the gains a day after the government released revised reimbursement rates for Medicare Advantage plans. The new numbers suggest that funding cuts will be less severe than analysts and companies had feared.UnitedHealth was the biggest gainer in the Dow, rising $2.77, or 4.7 percent, to $61.74 a share. DaVita HealthCare Partners led the S&P 500 higher, gaining $7.29, or 6.1 percent, to $127.20.Airline stocks fell sharply after Delta Air Lines said a key measure of revenue was hurt last month by government spending cuts. Delta fell $1.31, or 8.1 percent, to $14.94. United Continental lost $1.59 to $29.38 and US Airways Group fell 93 cents to $15.74.