Average Of A Calculated Measure

[_Moosa_]

I would like to create a bar graph in Power BI that shows the monthly trend of a particular number on selected months, along with a straight line representing the average of all the sums of selected months. Could you please assist me with the formula for calculating the average measure field?

[AnalyticPulse]

hello @_Moosa_ 
try below solution
create this measre for sum

MonthlySum = SUM('YourTable'[Number])

below measure for average
AverageMonthlySum =
AVERAGEX(
VALUES('YourDate'[Month]),
[MonthlySum]
)

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[_Moosa_]

Thanks for your reply but this dosent help i need a straight line foa average this solution calculates moving average on monthly basis.

[lbendlin]

Use AVERAGEX over ALLSELECTED.

[_Moosa_]

Still not working