Fit[{{-4, 17.4},{-3,9.3},{-2, 2.4},{-1,-0.08},{0,-0.4},{1,-0.07},{2,2.7},{3,9.3},{4,15.9}},{1,x,x^2},x]

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.