I am using CR 11, I am pulling data from a sql db.  I am creating a report that lists data from a table below:
Table: Historic_Data
year
month_number
entity_code
pounds
qtr 
year_qtr  

I currently have the data sorted by month and year_qtr (EX- 2009-Q1) and I have a Running Total that calculates the total pounds for each month.  So like below:

Months:                        Running Total:                   
May 2009-Q2                31,612.00
June 2009-Q2               308,254.00
July 2009-Q3                138,824.33

I also have another Running total that will display the average for each month.  It takes the running total and counts the values and divides it. so I then get this:

Months:                        Running Total:          Month Average  
May 2009-Q2                31,612.00                  1975.75
June 2009-Q2               308,254.00                5604.62
July 2009-Q3                138,824.33                7712.46

Now this is where I get stuck,  what I want to do now is display the Average for the QTR instead of the month.  So looking at the example above for 2009-Q2, I would like to have only the end of the qtr value displayed.

Months:                        Running Total:          QTR Average  
May 2009-Q2                31,612.00                  7580.37
June 2009-Q2               308,254.00                7580.37

I want this so when I graph it, it will have it where for the qtr's,, it will have the average.

Any ideas on how to do this?  Thanks in advance!