3. Alex found that the national average for all students who feel that taking "stats" with Prof. Yankey is necessary (for success) to be 80 with a variance of 25. She took a random sample of 81 students that shared this view and got a mean of 78. At a significance level of 2%, can she conclude that the number of students that share this view is different from 80? Find: a. What is the test statistic? (2pts.) b. Test the claim that the number of students that share this view is different from 2%. (3pts.)