Hello,

I have two columns that I would like to divide across and
sum the quotients. If the right column is not a number or is
0 or blank, I don't want to include it in the sum. Example:

[code]
A B C
1 Room Area Area/Person
2 Break 144.10 100
3 Office 157.70 50
4 Hall
5 Toilet
6 Stacks 785.00 100
.....
Total Occupants: ????

I would like to write a formula that would work with the
array and still work if I add rows or delete values. Some rooms
are not applicable to the count but need to be included anyway.

Tried the array formula:
{=sum(if(and(isnumber(C1:C6),C1:C60)),B1:B6/C1:C6))}

but it did not work. Sumproduct would work if I was trying
to multiply. Anyone have any ideas? Thanks.