working out an average, but not an easy one

Hi,

I am a university student (obviously not studying maths) and need to work out my average mark for my year.

I have taken 9 classes totalling 45 credits and my marks are out of 10. How can I work out my overall average mark out of 10 if the amount of credits differ?

6 credits 9/10 13.333%
4.8 credits 8/10 10.666%
4.8 credits 7.7/10 10.666%
4.8 credits 7.7/10 10.666%
4.8 credits 7.2/10 10.666%
4.8 credits 7.1/10 10.666%
4.8 credits 6/10 10.666%
4.8 credits 6/10 10.666%
5.4 credits 5/10 12%

Thanks to anyone that can help!!
Louise