Marks | Number of girls |
0-10 | 6 |
10-20 | 8 |
20-30 | 14 |
30-40 | 16 |
40-50 | 4 |
50-60 | 2 |
Marks | fi | Cumulative frequency | xi | |xi−M| | fi|xi−M| |
0-10 | 6 | 6 | 5 | 22.86 | 137.16 |
10-20 | 8 | 14 | 15 | 12.86 | 102.88 |
20-30 | 14 | 28 | 25 | 2.86 | 40.04 |
30-40 | 16 | 44 | 35 | 7.14 | 114.24 |
40-50 | 4 | 48 | 45 | 17.14 | 68.56 |
50-60 | 2 | 50 | 55 | 27.14 | 54.28 |
Total | 50 | 517.32 |