[Grammar] Preposition ‘in’ VS ‘out of’

[northpath]

Normally, I use preposition ‘in’ in such sentences as
1. 9 in 10 homes now have cable TV.
2. Three in ten people do not approve the bill.
3. His chance of surviving is one in three.

But from time to time I come across these sentences:

4. Nine out of ten people think that the government is right.
5. Last year, no fewer than one out of every eight seniors at Yale University …

So, are ‘in’ and ‘out of’ interchangeable?
1. 9 out of 10 homes now have cable TV.
2. Three out of ten people do not approve the bill.
3. His chance of surviving is one out of three.
4 .Nine in ten people think that the government is right.
5 .Last year, no fewer than one in every eight seniors at Yale University …
And if they are, should I prefer ‘in’ to ‘out of’?

 

[bhaisahab]

They are interchangeable in some cases. I would use "out of" in 1, 2, and 4.