The default mastery level is 80%. You might want to change this to correspond with your grading scale.
Open the My Classes page.
Click Classes › My Classes and find the section you want.
Click the Personal Study Plan tab.
Set the mastery level for chapter quizzes and practice quizzes.
Select the mastery level you want for Mastery level for chapter quizzes.
Select the mastery level you want for Mastery level for practice quizzes.
Click Save.