Agree with John, generally. Keep in mind...if you have some activities that have a required score, setting a course grade to pass might undermine that--if there are 500 points and 5 activities where you want 80% or better to pass each activity. With a required course grade of 400 (80%), a participant could score 50/90/100/100/70 and still 'pass' with 410 points--and that is with two failed activities. You might want to add activity completion requirements as well that, using John's example, only allow the last thing to display when you reach each requirement.
And be clear about the requirement--you must have 80% on each activity AND 80% overall. Sometimes students try to game the system.
Most activities have a grade by default (either one assigned on completion--quiz, scorm, lesson--or one you give manually--forums, glossary or assignments). You can set restrictions to require specific scores/completion before the next one is done as well.