quiz grades for groupA                          avg
9589-397  1  5  2 10                             5.67
7922-821  0  0  0  0                             0.00
3518-979 13 17 15 18                            16.67
4584-990 25 17 21 13                            21.00
7171-107  5 15  7  4                             9.00
1951-673  7 15 17  2                            13.00
1694-088 18 10  9  7                            12.33
6509-178  4 13 12  0                             9.67
6952-522  0  0  0  0                             0.00
2121-504 10 21 24  7                            18.33
6644-240  0  7 14 15                            12.00
2061-756  8 16 14 14                            14.67
5641-190 17  0  0  0                             5.67
2677-836 24  0  0  0                             8.00
5232-205 25 25 18 20                            23.33
6722-434 10 22 11  0                            14.33
9678-283 17  0 15 16                            16.00
6456-794 25 25 21 25                            25.00
0416-564  4 10  0  8                             7.33
the average was computed with  1 drop