rolling average without time intelligence

I solved my problem with the following:

Rolling 6 Weeks Average of Total Sales = 

//get the given week
VAR __given_week =
    SELECTEDVALUE('Dimension Week'[Week Number])

//number of weeks in rolling average
VAR __duration =
    6

//create a table of weekly ranges per week
VAR __calculation_range =
    FILTER(
        ALL('Dimension Week')
        ,[Week Number] <= __given_week
        && [Week Number] > __given_week - __duration
    )

RETURN
    IF(
        COUNTROWS(__calculation_range) = __duration //only return the result when there are the desired number of weeks in the range (e.g., week 5 doesn't have 6 weeks in it)
       ,CALCULATE(
            AVERAGEX(
                    'Dimension Week'
                    ,[Total Sales]
            )
            ,__calculation_range
        )
        ,BLANK()
    )