Given below is the observed data of the age of various boys. Study the table carefully and answer the question that follows.
| Age in years | Number of children (Boys) |
| 5 | 8 |
| 6 | 3 |
| 7 | 7 |
| 8 | 2 |
| 9 | 20 |
Calculate the mean age of the boys.
1
6.57
2
9.57
3
7.57
4
More than one of the above
5
None of the above