estimate mean

A dentist was interested in the effectiveness of new toothpaste. A group of N=1000 schoolchildren participated in a study. Pre study records showed there was an average of 2.2 cavities every six months for the group. After three months on the study the dentist sampled n=10 children to determine how they were progressing on the new toothpaste. Using the data in the accompanying table, estimate the mean number of cavities for the entire group, and place a bound on the error of estimation.
Child Number of cavities in the three month period
1 0
2 4
3 2
4 3
5 2
6 0
7 3
8 4
9 1
10 1