Try this:

=SQRT(SUM(INDIRECT("F"&M3&":F"&N3))/(N3-M3))

then copy it down as required.

Hope this helps.

Pete

On Dec 13, 6:38*pm, wileye wrote:
The formula I currently have is: =SQRT(SUM(F5280:F6240)/(N3-M3))
the row numbers 5280 and 6240 are values found in cells M3 and N3,
respectively.
However I need to copy this formula down a column, and I currently must go
through and edit each formula to change those two values to the neighboring
cells. *i.e. that formula is in cell O3, and when copied to O4 the desired
rows of column F to be referenced will be the numerical values in M4 and N4. *

=SQRT(SUM(F____:F____)/(N3-M3)) *please fill in the blanks?