Assuming I've understood you correctly, this should be what you want.

--Once again, I'll build your test data first

DECLARE @TABLE AS TABLE(

[RequestID] INT,

[RequestItemID] INT,

[CostLocal] FLOAT,

[Qty] INT,

[Total_doller] FLOAT)

INSERT INTO @TABLE([RequestID],[RequestItemID],[CostLocal],[Qty],[Total_doller])

SELECT 331, 1036, 123.0000, 2, 5.05776

UNION ALL SELECT 331, 1037, 100.0000, 3, 6.168

--Now to the query

SELECT [RequestID],

SUM([Total_doller]) AS [Total]

FROM @TABLE

GROUP BY [RequestID]

/*

RequestID Total

----------- ----------------------

331 11.22576

*/