LeastSquares[{{1, 5, 4, .5}, {1, 4, 4, 1}, {1, 6.8, 6.8, 18}, {1, 30, 40, 2}, {1, 50, 60, 2}, {1, 8.58, 8.58, 100}}, {5.5, 14, 60, 56, 82, 215}]

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.