try these
=IF(A19="","",(10^-A19)*100)
=IF(A1="",C1,(10^-A1)*100)
"BillO" wrote:

Hi

How can I calcualte an average in one cell from two different columns of
data depending on which is populated. Oh yea one column has a function
applied to it and if there is no data it returns a zero...I only want the
average if the data exists.

%T OD Convert OD to %T Test for blanks
10.00 1.00 =(10^-C19)*100 =IF()

1.00 10.00 10
1.00 10.00 10
5.00 0.00 0.001
2.00 1.00 1
0.50 31.62 31.6227766
100.00 100
100.00 100

See problem is when no data exists the log function takes "0" and turns it
into 100.

thanks