I'd base a bad mark on what the class average was because that would show how hard the test is. I'd always like to be ranked as high as possible in the class, after all rankings are what count towards your HSC when you reach year 12. If you get a bad mark, theres no need to be disappointed. It'll just be like a warning sign and can make you want to try harder. Next time, put in more effort and it'll eventually pay off. Remember if you're still in Year 9/10, you have time to develop great skills and work on your assessments so that come HSC year, you are ready to beast those assessment tasks.