2. Answer this question by both solving by hand and showing your work and Using R to check your answer. A sample consists of 75 TV sets purchased several years ago. The replacement times of those TV sets have a mean of 8.2 years. Assume o= 1.1 years. Find the 95% confidence interval. 4. Answer this question by solving by hand and showing your work. A random sample of 61 Foreign Language movies made in the last 10 years has a mean length of 135.7 minutes with a standard deviation of 13.7 minutes. Construct a 95% confidence interval. 5. For items 2 and 4, you are constructing a confidence interval. What is the critical difference in the construction of those intervals