With only the information you've provided, the best I can do is:
WHERE 4 < (Coalesce(Value1, 0) + Coalesce(Value2, 0)
+ Coalesce(Value3, 0) + Coalesce(Value4, 0)) / 4
When working with columns within a row, you can easily derive the formulas for things like an average. The aggregate functions are provided for more difficult cases where you have arbitrary numbers of rows.
and guys, both of ya get minus 10 marks for the evil dreaded "select star"
Sorry, you can't take points away unless the specs contain enough information to avoid the problem. We only got the names of the columns of interest, no posted DDL, so we had to use * to ensure a complete answer!