Standar deviation across sheets help
 

I have written a formula that will take what is written in Column A of my Cover sheet and match it to Column A of all the other worksheets (other worksheets defined as "CMM_Dates") which will in turn take the Column E values of all the CMM_Dates worksheets (with a match in Column A) and average them.

=SUMPRODUCT(SUMIF(INDIRECT("'"&CMM_Dates&"'!$A:$A" ), $A2, INDIRECT("'"&CMM_Dates&"'!$E:$E"))) / (COUNTIF(CMM_Dates,"*"))

MY QUESTION:

Can I take this Equation, and instead of averaging the values taken from Column E of the CMM_Dates Worksheets, can you help me ReWrite the formula to take a Stand Deviation of the values taken from Column E of the CMM_Dates Worksheets?

Any help would be greatly appreciated

Thank you,