Misconceptions about group bonus

[Widan]

I just want to clear up how it is broken down since people seem to be under the impression having afk people in your group is actually beneficial.

Let's say a mob kill is worth 1000 exp on blue.

1 person on red @ 50% bonus = 1500 for the soloer
2 @ 100% = 2000/2 = 1000 per person
3 @ 150% = 2500/3 = 833.33 per person
4 @ 200% = 3000/4 = 750 per person
5 @ 250% = 3500/5 = 700 per person
6 @ 300% = 4000/6 = 666.66 per person

Is this correct? Because it is noticably faster for me to solo/duo still than group with afk'ers or in a subpar group.