Are there only 2 records? Are there always a pair of records to do the calculation on throughout the entire table?

>Hi all,
>
>Two records in one table
>
>table1.dbf
>
>number :
>
>2 first record
>4 second record
>
>2/4 or 0.5 or 50% to newly 3rd record in the same table.
>
>Any source code that leads to the solution would be greatly appreciated ?
>
>Paul