This is what I think the formula should read:
=IF(K18<SUM(k87+110)SUM(K87+90),SUM(K18+800),"")
Excel doesn't agree. I'm trying to say that K18 is an entry cell and if
that value falls between K98+100 (+/-10) that the result will add 800 to K18.
If it falls outside of the +/- range, then the value will return blank.
Help please!