DEVSQ

In my recent quest to create or catalog as many DAX equivalents for Excel functions, this was another walk in the park:

DEVSQ = 
    VAR __Mean = AVERAGE('Table'[Column1])
    VAR __Table = 
        ADDCOLUMNS(
            'Table',
            "Deviation",POWER([Column1] - __Mean,2)
        )
RETURN
    SUMX(__Table,[Deviation])

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