I see from the FAQ that the basic attendance for the 4th div is 42'000.

Does this mean that 42k is the bare minimum that you will get for a game in D4 if your stadium has this capacity?

Is it only once you go over 42k that the attendance figures start to vary due to weather/form etc in this Division?

From experience:

The core is a +30% to -30% variation of the basic attendance

By the end of season the Divisionleader can even have up to a +50%...

...on the other end: a team at the bottom of the league table with an "awesome negative record" can also have a -50%