sql server daily average

Question

What's the best way to get a daily average. The data would have 2 values per day, for example:

Date             Value
1/1/2012 4:00    10.00
1/1/2012 16:00   11.00
1/2/2012 4:00    11.22
1/2/2012 16:00   13.55
etc.

Answer 1

Select CAST(DateColumn as date), AVG(Value)
From Table
Group By CAST(DateColumn as date)

Answer 2

select date, avg(value)
from yourTable
group by date