I need to write a formula for finding a % of a series of rows. However some
of the rows are not applicable.
Examle of what I am trying to make happen:

a | b | c | d
1 | 0 | 1 | 1 = 75%
| 1 | | = 100%
0 | 1 | | = 50%

The blank cells dont have a value so I dont want them to reflect in the
result. I dont know how to write a formula to only use cells that have a
value.

What i have now is (a1:a4)/?? What do I divide it by.

Please reply to