Check this site for SUMPRODUCT as an alternative to array functions:

http://xldynamic.com/source/xld.SUMPRODUCT.html
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Kind regards,

Niek Otten
Microsoft MVP - Excel

"Dave F" wrote in message ...
| Here's the formula:
| =SUM((C31:C46)*(E31:E46))-SUM((C47:C51)*(E47:E51)/2)+SUM((C54:C59)*(E54:E59))+SUM((C67:C71)*(E67:E71 ))
|
| My guess is that these are matrices being multiplied together and matrix
| algebra is different than straight multiplication. So, Excel requires
| CTRL+SHIFT+ENTER to tell its calculation enginge to do matrix
| multiplication....
|
| Am I correct here?
|
| Also: it seems to me that the same calculation can be done with SUMPRODUCT.
|
| Dave
|
| --
| Brevity is the soul of wit.