How do I add a running total column?

[Anonymous]

Hi! I'm new to DAX.

I tried adding a new column and a new measure to a table with two columns: Date and 15 year interest rate. 

What is wrong with my formula? 

Running total(MEASURE/COLUMN) = CALCULATE(MAX('Interest rates by month'[15 year rate]),DATESINPERIOD('Interest rates by month'[Date],MAX('Interest rates by month'[Date]),-30,DAY))

Here is the table: 

[amitchandak]

@Anonymous , max for cumulative total ??

it need to like

Running total(MEASURE/COLUMN) = CALCULATE(MAX('Interest rates by month'[15 year rate]),DATESINPERIOD('Interest rates by month'[Date],MAX('Interest rates by month'[Date]),-30,DAY), filter(allselected('Interest rates by month'), 'Interest rates by month'[Date] <=max('Interest rates by month'[Date])))

or

Running total(MEASURE/COLUMN) = CALCULATE(SUM('Interest rates by month'[15 year rate]),DATESINPERIOD('Interest rates by month'[Date],MAX('Interest rates by month'[Date]),-30,DAY), filter(allselected('Interest rates by month'), 'Interest rates by month'[Date] <=max('Interest rates by month'[Date])))

This usually we use for running total

Cumm Sales = CALCULATE(SUM(Sales[Sales Amount]),filter(allselected(date),date[date] <=max(date[Date])))
Cumm Sales = CALCULATE(SUM(Sales[Sales Amount]),filter(allselected(Sales),Sales[Sales Date] <=max(Sales[Sales Date])))
Cumm Sales = CALCULATE(SUM(Table[value]),filter(allselected(Table),Table[Date] <=max(Table[Date])))