The most valid response is:
No, because not all students in the sample have extracurricular activities.
This conclusion is important because if the sample includes students who do not participate in any extracurricular activities, it could skew the average down. To accurately determine the average number of extracurricular activities per student, the sample should include students who represent the whole population in terms of participation. Including only those with extracurricular activities would give a biased view of the average for the entire student body.