I am in a Stats class and the professor uses SUMPRODUCT(range1,range3)*SUMPRODUCT(range2,range4) and SUM(range1*range2*range3) to show relationships between the data, but from some reason when I hit F9, the SUM functions all show #VALUE!. Is there something I need to enable in Excel to make this work? Was this functionality removed? I am using Excel 2013.

The formulas for the two calculations above are:
=SUM(E65:H65*D66:D69*E66:H69)
=SUMPRODUCT(H60:H63*I60:I63)^2

If I edit the formula and hit enter (NOt make any changes, just go into it and hit enter), the top formula will return #VALUE!. In addition, I noticed after that happens if I go to the Fx in the function bar and open the properties the answer shows correctly! Any idea what I am doing wrong?

Thanks!

Tony

With regards to SUM, you'll need to confirm the formula with CONTROL+SHIFT+ENTER, not just ENTER.  If done correctly, Excel will automatically place curly braces {...} around the formula.

Hope this helps!

AHHHH, I was wondering where those came from! I kind of  figured that was the missing link because I was unable to manually enter them. What is that for?

Simply, it signifies to Excel that we're dealing with an array formula...