The data has occasional blanks in it becasue not all students are required to
take all of the tests. Bob, the formula you gave worked great when every
student took a specific exam. However, when there was a blank cell (i.e. no
exam taken), the formula treated the cell as a zero value instead of just
igonring it. this obiviously skewed the results


"Bob Phillips" wrote:

In what way? What did you get?

Your original data didn't have any blanks. Can you show the data and formula
that didn't work?