For me, that returns #N/A for

**all **values in A2 except errors other than the #N/A error

If we only want "NO" returned for #N/A errors and not other errors then for your version (I think 2010?) you would need

=IF(ISNA(A2),"NO",IF(A2>0.7,1,0))

or for subsequent versions the If(ISNA .. has been compressed into a single function

=IFNA(IF(A2>0.7,1,0),"NO")

@

**Rookieeee**
Also note that in any of the suggeted formulas IF(A2>0.7,1,0) can be replaced by --(A2>0.7)

For example, the formula you chose can also be written as

=IFERROR(--(A2>0.7),"NO")