Prof. SoftTouch gave three exams last semester. Scores were normally distributed on each exam. Below are scores for 10 randomly chosen students on each exam. (a) Find the 95 percent confidence interval for the mean score on each exam. (b) Do the confidence intervals overlap? What inference might you draw by comparing the three confidence intervals?
Exam 1: 81, 79, 88, 90, 82, 86, 80, 92, 86, 86
Exam 2: 87, 76, 81, 83, 100, 95, 93, 82, 99, 90
Exam 3: 77, 79, 74, 75, 82, 69, 74, 80, 74, 76