Here’s a quick video from HowtoMoodle which helps to showcase the process of setting minimum passing scores for quizzes in Moodle. This is a key feature if you’re tracking specific proficiency levels within Moodle and tracking completion (but remember to provide students more than just one chance if the stakes for completing are high).
This is a new feature for the quiz in Moodle 2.9 (though in previous versions you can also set this at the gradebook level): https://docs.moodle.org/29/en/New_features#Grade_to_pass
Check out the video at http://www.howtomoodle.com/blog/moodle-tips-vlog-setting-pass-grade-moodle-2-9/ or click the image below.
Note: HowtoMoodle is a supporter of Moodlenews.com