How to do it...

To implement this recipe, perform the following steps:

1. Create the following measure:

Rolling Week Average = 
    VAR __Date = MAX('R09_Sales'[Date])
    VAR __Sales = ALL('R09_Sales')
    VAR __WeeksBack = 4
    VAR __WeeksForward = 0
    VAR __RollingWeekStartDate = __Date - 7 * __WeeksBack
    VAR __RollingWeekEndDate = (__Date + 7 * __WeeksForward) - 1
RETURN
    AVERAGEX(
        FILTER(
            __Sales,
            [Date] >= __RollingWeekStartDate &&
                [Date] <= __RollingWeekEndDate
        ),
        [Value]
    )

2. Create a Line Chart visualization and place the Date column from the R09_Sales table in the Axis field and the Rolling Week Average measure in the Values field.