Exclusion of one record for Averages.

[m3gd04]

I work in a hospital and we're trying to find the average turnover time between cases in each of our Surgery rooms however we need to exclude the first record for obviously this would be N/A. I'm hoping this is something pretty easy to solve:


I have the following fields in a table:

Case Date Case # Room Start Room Stop Time bet cases

07/01/04 001 8:22 10:05 0.00
07/01/04 002 10:49 13:09 44.00
07/01/04 003 13:45 15:17 36.00

avg: 26.66 min


The "Time bet Cases" variable has the written formula:
=If <Case Date>= Previous (<Case Date>) Then <Room Start Time Value>-Previous(<Room Stop Time Value>) Else 0

Again, my question is: How can I exclude the first record so that the average is from the 2nd line down. In other words the record should reflect 40 minutes rather than 26.6 if we exclude the value of "0" from the first line item record.

Any help would be greatly appreciated...

Thanks

 

[skrandel]

You can't use a simple average. You have to build the calculation yourself as:
sum(<Time bet Cases>)/(Count(<Case #)-1)

Steve Krandel
VERITAS Software