Lost in Numbers

The statistic teachers at Karlstad University must be sadist. There is no other explanation to this amount of illogical mathematical equations they have in their tests. Mathemathic is supposed to be the most logical subject of them all, 1+1=2 whatever you think. Eqations have one purpose and they can't be shanged and so on. These statistical teachers seems to recreate the mathematical laws right in front of me. The book gives us this special formula for one purpose and it's alright you think, but no. They use another one, same purpose apparently and almost the same numbers, almost. Or it can be the same formula, if you remeber all the special conditions to use it that is. And then there is another condition that are fullfilled and you need a correction factor and then a third rule of some kind.

All this you must keep in your head and without warning they throw in the answer and say "yes, you had the right idea, unfortunately for you we decided to take this correction factor and change it a bit which will screw your numbers up and the whole answer, but good thinking". And they never explain this in their answers. Numbers fly out of nowhere and are put in tese calculations. And the most annoying is to determine whether it is a z-score or a t-distribution. They just ad [table] and give you some number without logic. And when you think you have it they decide to round it up and completely destroy your theory. How in gods name am I supposed to understand this when they change the rule all the time? Thank god it is just 1 week left. I can't handle much more.