I'm working with a spreadsheet where we are tracking a few variables
that are later calculated into a mean. Generally there are alwats 5
variables in each mean, but every so often on of the conditions is not
met so that cell returns "FALSE" or "#N/A". In those cases excel
figures them as zeros in the mean.

Is there a way to have excell recognise the occurance of a "FALSE" or
"#N/A" and not bring it into the mean calculation?

So if one of the 5 variables returns "FALSE" or "#N/A" I would like
excell to do the mean based on the other 4 using a devisor of 4.

Any ideas?