A psychologist developed an behavioral intervention designed to reduce test anxiety associated with taking Exams. He wondered whether the intervention would work differently with middle school students compared to high school students. He randomly selects 80 seventh-graders and 80 ninth-graders, and administered her intervention to half of each group (within each grade, students were randomly assigned to receive the intervention, while others did not receive the intervention). Subsequently, she measures the anxiety of each student just prior to the start of the Exams.
- What type of test is needed to analyze the data?
- What is the hypotheses (including the symbols used to state the hypothesis)?