I also have a fox float R shock on my Trance - the recommended sag for my bike & that shock is 9mm (which I think is 25% of the travel). This figure may be different for yours.
You will need a shock pump to set the correct sag to start with (refer to your bike manual & shock manual to find out the correct sag, which changes according to the pressure you pump the shock to according to your weight- or ask your LBS).
Once that's done take it for a ride & see if it's still happening - if it's still happening try adjusting the rebound damping knob (red dial). I only realized yesterday I've been running mine at the "least" rebound damping end and it seemed to ride pretty well if a little bouncy at times-only rarely - on smoother or flatter trails the more rebound damping you have the more bouncy it would be from my understanding - and there are no hard and fast rules for settings, I think it depends on your weight and other factors too. The more you weigh the more rebound damping you may need.

So if you think the sag is already correct then try playing with the rebound knob. The fox float R doesn't have a lockout (I find it doesn't need it on on the Trance anyway) but the fork lockout does make a big difference in regards to not sapping energy on the road or up hills.