>Say I have a set of data that is the price of a home.
>
>100,000
>125,000
>92,000
>175,000
>135,000
>10,000
>500,000
>
>Well, I know that the 10,000 fiqure is really just for a lot. So when figuring trends, I need to throw it out. I also know that the 500,000 fiqure is also way off, so it too needs to be thrown out.
>
>If each of these numbers were in a field in a dbf(one per record) How could I programmatically throw out numbers that were way off? I have tried diffrent forms of average and standard deviation, but nothing seems quite right. I need some high school algebra or statistics lessons I think.

If you're seeking trends, I'd think about using the median. The housing industry actually often uses this (the middle value of the set from a specific time period). How about that?