How can I output audio at 48khz? Very noob question, I know, but I can't find the answer on Google or in the manual. 

I'm editing a movie file in the VSE, and nothing else. When I want to render it out, the audio is at 44.1kHz, and I'd like it to be 48kHz. I can't find the setting for that anywhere. 

The audio I've imported is already at 48kHz.

Can anyone point me in the right direction?
In the 'Scene' buttons, there is an Audio Panel. It has a Format: label, under which you can adjust the Channel count and Rate.

Then you can render Audio from the render panel (also known as Mixdown).