One thing you can do, is to add an extra column in the grade book, which is a scale, and where the value is calculated from the quiz score.
That is not really what you want, because the scale value will not be shown in the quiz, only in the gradebook.
Thanks Tim. That's exactly what I did. I added a new grade item for the quiz result and this now records using the "Satisfactory" scale. You can also hide the quiz results from the gradebook so they can only see the new grade item. Students can see the results in the activity but not in the gradebook. Great!