Running Weekly Average

I've read some posts but I can't quite find what I need.  Basically we carry out several house repairs per day.  So I use a simple CALCULATE ( COUNT on the PK: JobNumber to get the number of jobs per day.  I then used the following DAX to work out a running daily average: -

// 

Average No of Repairs = 
                    AVERAGEX (
                                FILTER (ALLSELECTED ('Date'),
                                        'Date'[Date] <= MAX ('Date'[Date]) ),
                                [Number of Repairs]
                    )

Which gives me a table like this: -

I want to produce a line graph that shows me the data on a weekly basis, So I added a calculated column into my date table that works out the week ending date for any given date (Ending Sunday).  So when I remove the Date column and add the WeekEnd Date I get this: -

So it seems like it is picking up the average figure at the end of each week.  What I technically need is a SUM of those 7 day averages, but I can't seem to reference the Average measure when creating a new CALCULATE(SUM measure.  

Maybe there is a better way to do the entire thing?  I also have month number in my Date table if it helps.  

Any help would be appreciated.

Cheers,

JP