My engineering brain says it’s 3.25.

4% is ~ 5%. 10% of 75 if 7.5. To get the 5% I have to divide it by 2, so 4% of 75 is close to 3.25. I will have to multiply it with some safety coefficient at the end, so the exact value doesn’t matter.

That’s why you can always double the maximum limits engineers give.

60 mph roadway?

I can do 120 on it no problem.

Eight person elevator? Sixteen.

0.08 BAC? 0.16 easy peasy.