Tween class tutorial

Hi all, I’ve been working through the tween class tutorial and I can’t work something out. I may be being stoopid but what do the three values at the end of the third line refer to?

var xScaleT:Tween = new Tween(star, “_rotation”, Elastic.easeOut, 10, 360, 40, true);

Obviously ‘360’ refers to the angle of rotation but when I alter the first and the third value they both seem to do the same thing and change the speed.