I dont know about that equation, but I do it simple. Same for upper and lower for me though.
When Bulking or adding power:
I do 8-10 reps warmup or lower weight
Then 6-8 reps median weight
Lastly atleast 4-6 heaviest weight.
Sometimes I just do it all until my exhaustion and I cant do one more, of course with the best form and technique. Also, more time between resting periods.
For cutting or loosing some cals:
I do 14-16 reps warmup or lower weight
Then 10-12 median weight
Lastly, 8-10 heaviest weight.
This is usually all done to exhaustion with super concentration on muscle stress and best form and technique whether negative or positive contractions. Also, less time between resting.