For a recent year, the mean fare to fly from Charlotte, North Carolina, to Seattle, Washington, on a discount ticket was $267. A random sample of round-trip discount fares on this route last month gives:
$321
$286
$290
$330
$310
$250
$270
$280
$299
$265
$291
$275
$281
At the .01 significance level, can we conclude that the mean fare has increased? What is the p-value?