Ernie Ball Power Slinky Bass 5 vs Bass 4

[Joronamo]

Just wondering why the Bass 5 Power slinky set is .05 lighter than the bass 4 power slinky set? The standard bass 4 pack has 55, 75, 90, 110 gauges and the bass 5 pack has 50, 70, 85, 105, 135 gauges. Obviously the low B string is irrelevant in my inquiry but as yo can see the other 4 stringer are lighter. Thanks for help.

[JimWasHere]

if you figure each string at 25 lbs tension (I know it's not quite accurate, it's the math that I'm making the point with) then 4*25=100. If the 5 string set shaves off 3 lbs per string from the lighter gauge, then 22*5 110, vs 25*5=125. Less tension is = to less setup and playability issues, and less player fatigue (which is arguably more with a wider fretboard).

Of course everything I just said is theory.