I need help with these! not sure how to solve a 2 sided confidence interval for differences in N or the U of the tire. Please help!

Task 1 (of 2) Assume that the gain in a circuit on a semiconductor device is normally distributed with standard deviation o = 20. a) Find a 95% two-sided confidence interval for u when n = 10 and X= 1000. b) Find a 95% two-sided confidence interval for u when n = 25 and X= 1000. c) Find a 90% two-sided confidence interval for u when n = 10 and = 1000. In the Conclusion section of the Problem Presentation Method, discuss how the length of the confidence intervals computed above change with the changes in sample size and confidence level? Task 2 (of 2) A research engineer for a tire manufacturer is investigating tire life for a new rubber compound and has built 16 tires and tested them to end-of-life in a road test. The sample mean and standard deviation are 60,139.7 and 3645.94 kilometers, respectively. a) Find a 95% two-sided confidence interval for u tire life. b) Find the 90% lower confidence interval for u tire life. c) Find the 99% upper confidence interval for u tire life