Suppose that Drake works for a research institute in Greenland and is given the job of treating wild polar bears there for hypothyroidism using medicated darts. The appropriate dosage depends on the bear's mass. Eager to head into the wilderness, he prints out the statistics he needs and sets off, planning to prepare the darts along the way.

Two days into his trek, however, Drake spills a cup of coffee on the printout. Unwilling to admit to his boss what happened, he decides to estimate the polar bear mass with the information he has remaining. He knows the population standard deviation to be =60 kg, and he has data from a simple random sample of = 10 polar bears from Greenland. Their masses, in kg, are

275 250 325 310 240 360 350 400 380 400

The sample mean polar bear mass is =329 kg.

Next, calculate the lower and upper limits (bounds) for a 99% confidence interval for the mean polar bear mass in Greenland. Give your answer precise to one decimal place.