看你是什么学制的吧,如果是两学期制的：
The student's semester work is worth 30% of his/her final course grade. This student got (或has earned) X for his semester work.
The student's semester exam is worth 70% of his/her final course grade. This student got (或earned) Y for his exam grade.
其他学期制的有quarter, trimester, annual等,分别是四学期、三学期、一年.但最常见的还是两学期吧.
因为你问的是期末成绩,所以我这样回答.但也有两年的课程的,如果是那样,就直接course work跟final exam就行了.
exam跟examination是一样的,你如果求正式就选examination吧……
还有,以上只是建议,但其实你翻的也可以,语气也正式.
但如果保留你的翻译,我会把Class放在最前面,Class assignments and performance.
不过总觉得这样有点repetitive,因为assignments是包含在performance里的不是吗?但不说又觉得不够详细不知你在说什么……所以还是建议直接用course work吧.