Third cylinder malfunction? on 2009 Chrysler PT Cruiser

This morning, when I started up my car, it was shaking a bit. After turning the car off and on twice the car felt normal, but the engine light was still on. The car also seemed fine the night before. According to the diagnostic from autozone it said it was a third cylinder malfunction. What does this mean, and does anyone have any idea what it costs to fix?

Asked by for the 2009 Chrysler PT Cruiser
Its detecting a miss fire on that cyl , theres a bad plug , wire or coil ir injector on that cyl..