Ha! Steve beat me to it. Love seeing different approaches to challenges. Although I couldn't find the one I built back then so just put this together to show another approach.
I just used the existing Results.ScorePoints variable off the Next button on the Results slide.
Pre-assessment has four (4) questions each worth 25 points. No Pass/Fail rather the results direct the learner down a path based on their score.
- If the learner gets less than or equal to 25 points, they go to the Beginner Path
- If the learner gets equal to 50 points, they go to the Intermediate Path
- If the learner gets greater than or equal to 75 points, they go to the Advanced Path.
DEMO
p.s. Agree with Steve on tracking averages. Can be tricky. If there's not a need for that try and stick with an even number easy to be divisible for purposes of calculating the weighted points per question. e.g. 10 questions at 10 pts each = 100 points, 4 questions at 25 pts = 100 points , 5 questions at 20 pts each = 100 points, etc. Keep folks like me sane who don't like math 
learner-path-by-pre-assessment-score.story