Calculated Column on a temp table

This is what I did but there is perhaps a better way.  I first created a summarized table then I did the calculation based on that: -

_CalcTable Weekly Repairs = 

VAR _ALTTABLE = 
        ADDCOLUMNS (
                       SUMMARIZE ( 
                               'Repairs General',
                                'Date'[Week Starting Date]),
                                "No of Repairs", CALCULATE (DISTINCTCOUNT ('Repairs General'[Job Number as integer]))
        )
RETURN 
    _ALTTABLE

Here is a calcualtion based on that table: -

Average Weekly No of Repairs = 
//This uses the calculated table CalcTable Weekly Repairs to work out the average
 
    AVERAGEX (
                FILTER( 
                        ALLSELECTED(
                                    '_CalcTable Weekly Repairs'),   
                                    '_CalcTable Weekly Repairs'[Week Starting Date] <= MAX ('_CalcTable Weekly Repairs'[Week Starting Date])), 
            '_CalcTable Weekly Repairs'[No of Repairs]
    )<div> </div>