The correct response is:
No, because not all students in the sample have extracurricular activities.
The conclusion drawn by the principal is not valid because if the sample includes students who may not be involved in any extracurricular activities, it could skew the average participation rate. Including students who do not participate at all would lead to an average that is not representative of those who actually do participate in extracurricular activities. For accurate results, the sample should consist solely of those students involved in extracurricular activities.