some questions regarding to preposition

Hi,

It keeps confusing me whether "of" or "for" is correct in some situation.

Here are the sentences that I came across in my college material.

1) The cost per account of last month is $16
2) Assuming the data of each cost driver level for the last month is also collected as follows:

I am wondering if they are both correct? If no, which preposition should the sentence use?
If they are both correct, I am wondering if both "of" and "for" fit both sentences? What I am saying is, can sentence 1) & 2) use either "of" or "for" and still expressing the same meaning??

What makes me confused is: If 1) is correct, then why sentence 2) has to use "for" as the preposition? shouldn't it be "Assuming the data of each cost driver level of the last month is also collected as follows:" ??

and here
3) Chapter 3 page 48-50 in your textbook .....
4) ....as stipulated in Chapter 4 pages 100-101 of your textbook.

So, are they both correct? If yes, I am wondering why sentence 3) uses "in" but sentence 4) uses "of" when they are basically talking about the same thing.
Can sentence 4) be "....as stipulated in Chapter 4 pages 100-101 in your textbook." ?

Thank you very much for your help.