Hi, here's a challenging issue:

What formula could I copy for all cells in Column A so that will
automatically show "No" "Yes" or a blank cell automatically.

Note that:
No = the bottom half of a series of numbers
Yes = the top half of a series of numbers (for odd series, there are always
1 more "yes" than "no"
blank cell = for every cell in column b that = "@NA"
"@NA" is not a formula generated error, it's "hard coded" into the cell

See below for an example spreadsheet.

Thanks very much for any help!

ColumnA ColumnB ColumnC
No 1 Apples
No 2 Apples
Yes 3 Apples
Yes 4 Apples
Yes 5 Apples
No 1 Oranges
Yes 2 Oranges
@NA Oranges
No 1 Pears
etc