Moving Average without dates

HI Anonymous

One approach is to add an Index column and then use that to generate your "last three items" average.  I have attached a PBIX file (you can hide the Index col if you like).

The index calculated column can be added like this

Index = RANKX('Table1','Table1'[Date],,ASC) 

With the moving average column using it in this way

Moving Average = 
VAR MyIndex =  Table1[Index]
VAR myResult = 
    AVERAGEX(
        FILTER(
            'Table1',
            'Table1'[Index] > MyIndex-3  && 
            'Table1'[Index] <= MyIndex
           ),'Table1'[Value]
           )
RETURN FIXED(myResult,2)