According to the result of a QA test, when handling multiple attempts, the "Average" and "Last attempt" calculations are incorrect.

It could be that these have been tested incorrectly or there could be a bug.

Replication instructions (from the QA test):
This test requires a SCORM 1.2 package which can handle multiple attempts (see http://docs.moodle.org/en/SCORM_FAQ#Handling_of_Multiple_Attempts ).
Ensure 'Auto continue' is set to "No".

1. Login as a teacher, edit the settings for the SCORM activity, set the grading method to 'Highest grade', the number of attempts to unlimited and the attempts grading (an advanced setting) to 'Highest attempt'.
2. Login as student1, attempt the activity 3 times and check that the grade recorded in the gradebook is the highest attempt score.
3. Login as the teacher, edit the settings for the activity and set the attempts grading to 'Average attempt'.
4. Login as student2, attempt the activity 3 times and check that the grade recorded in the gradebook is the average of all attempts.
5. Login as the teacher, edit the settings for the activity and set the attempts grading to 'First attempt'.
6. Login as student3, attempt the activity 3 times and check that the grade recorded in the gradebook is the score for the first attempt.
7. Login as the teacher, edit the settings for the activity and set the attempts grading to 'Last attempt'.
8. Login as student4, attempt the activity 3 times and check that the grade recorded in the gradebook is the score for the last attempt.