Solve the following:
Q: Prof. Hardtack gave three exams last semester in a large lecture class. The standard deviation s = 7 was the same on all three exams, and scores were normally distributed. Below are scores for 10 randomly chosen students on each exam. Find the 95 percent confidence interval for the mean score on each exam. Do the confidence intervals overlap? If so, what does this suggest?
Exam 1: 71, 69, 78, 80, 72, 76, 70, 82, 76, 76
Exam 2: 77, 66, 71, 73, 94, 85, 83, 72, 89, 80
Exam 3: 67, 69, 64, 65, 72, 59, 64, 70, 64, 56