A mid$-$sized company has decided to implement an enterprise resource planning $($ERP$)$ system, and management suspects that many of its employees are concerned about the planned implementation. Managers are considering holding informational workshops to help decrease anxiety levels among employees. To determine whether such an approach would be effective, they randomly select $16$ employees to participate in a pilot workshop. These employees were given a questionnaire to measure anxiety levels about ERP before and after participating in the workshop. To determine if anxiety levels about ERP decreases as a result of the workshop, they should use a