it's perfectly feasable to have a fraction as an average, but if you want rounding up, we can do that too.
I usually get about 5 - 8 hours of sleep each night, just like i did in college (only a few years ago). It's such a wide range because it depends on if i'm tired or not, literally. Sometimes I won't be tired until 7 or 8, and then i'll sleep until 1pm and be perfectly fine with 5 hours' sleep... and sometimes I'm tired at 5am, and sleep until 1 and get a solid 8. It's almost like my body knows when I'll be getting up and depending on how much recharge i need, i feel tired at the right time.