Grouping data checking against top values
This should be what you're looking for.  If not can you update the question with an example of the expected output?  Thanks.  If you haven't used CTEs before note that the statement before the CTE needs to be terminated with a semicolon.

DECLARE @calldata TABLE (
    CallNum INT,
    value NUMERIC(25,20),
    Accepted CHAR(5)
);

INSERT INTO @calldata VALUES
(971374,81.482204444473609,'True'),
(971374,83.783551111089764,'False'),
(971374,97.936875555547886,'False'),
(971374,97.936875555547886,'False'),
(971374,77.037724444409832,'False'),
(971374,83.783551111118868,'False'),
(971375,102.35080888887751,'False'),
(971375,99.664653333340539,'False'),
(971375,101.41519999998855,'True'),
(971375,98.415355555567658,'False'),
(971375,90.222848888864974,'False'),
(971375,100.160346666642,'False'),
(971375,103.59455111110583,'False'),
(971375,90.222848888864974,'False'),
(971333,74.722782222175738,'False'),
(971333,95.24945333332289,'False'),
(971333,98.315848888887558,'False'),
(971333,95.24945333332289,'False'),
(971333,98.315848888887558,'False'),
(971381,93.169031111086952,'False'),
(971381,78.444248888874426,'False'),
(971381,86.4358755555586,'False'),
(971381,101.53599999999278,'True'),
(971381,86.438653333345428,'False'),
(971381,80.975364444457227,'False'),
(971383,86.3230488889094,'False'),
(971383,86.3230488888803,'False'),
(971383,86.3230488888803,'True'),
(971383,86.3230488889094,'False'),
(971385,33.150697777775349,'False'),
(971385,33.150697777775349,'False'),
(971385,27.780991111125331,'False'),
(971385,27.780991111125331,'True'),
(971333,98.315848888887558,'False'),
(971333,54.750293333345326,'False'),
(971333,98.315848888887558,'False'),
(971333,95.24945333332289,'False'),
(971333,95.24945333332289,'False'),
(971390,101.3407733333006,'False'),
(971390,95.90560444444418,'False'),
(971390,85.444066666648723,'False'),
(971390,95.908382222231012,'False'),
(971390,101.3407733333006,'True'),
(971390,85.444066666648723,'False');

WITH maxCallNum AS (
SELECT CallNum, value, Accepted, rowNum = ROW_NUMBER() OVER (PARTITION BY CallNum ORDER BY value DESC) FROM @calldata c1
WHERE EXISTS (SELECT 1 FROM @calldata c2 WHERE c1.CallNum = c2.CallNum
    AND Accepted = 'True')
)
SELECT CallNum, value, Accepted
FROM maxCallNum
WHERE rowNum = 1;