I have a report with a grouping and the details,

basically data is like this
x y z
200 test 80.00
200 test2 80.00
200 test3 80.00
300 abc 20.00
300 abc2 20.00
300 abc4 20.00
400 zzz 50.00
400 zzz 50.00

basically I'm grouping by x showing y for the detail and z for the total for each grouping but not as a sum, it's the total repeated in each item of the grouping, so the grouping totals would be:

200 = 80.00
300 = 20.00
400 = 50.00

Grand Total = 150.00

How can I accomplish this?