2003 ford explorer sport sub question.?

I have a 2003 for explorer sport. i got this subwoffer that i want to install in it, but i dont know if my stock radio has a sub feed. i was wondering if it did or not? im pretty dumb when it comes to car stuff, but i understand audio stuff. so i just wanted to know if the stock radio has a sub out feed, or if im going to have to get a new deck. please let me know, and any websites with more info will help. thanks.