Did you read the application requirements before you sent the application?
Do you know how to play bass? Have you played bass before? Do you read music?
How long do you have to play?
If you can't be prepared in time, call off the audition. Don't waste anyone's time and ruin your reputation from the start.
Why did you apply? What did you expect? You'll be competing with people who already know what they are doing.
You might want to check out the following TB thread:
So you want to be a music major?
Good luck.