Using one-sample hypothesis testing.
In a high school, Mark's class took the admission test for business school and averaged 83.4. For all the 10 classes taking the same test, their scores are (including Mark's): 78.2, 90.5, 89.6, 80.1, 75.4, 83.4, 81.7, 92.6, 93.8, 85.9. How did Mark's class do in the admission test? There are 25 students in Mark's class taking the admission test, and here we assume that the average test scores of all the 10 classes follow a normal distribution.