Please assist with the attached.

1. A population is known to be normally distributed with a standard deviation of 2.8. a. Compute the 95% confidence interval on the mean based on the following sample of nine: 8, 9, 10, 13, 14, 16, 17, 20, 21. b. New compute the 99% confidence interval using the same data. 2. Ten A survey of 35 individuals who passed the seven exams and obtained the rank of Fellow in the actuarial field find the average salary to be $150,000. If the standard deviation for the population is $15,000, construct a 95% confidence interval for all Fellows. 3. A meteorologist who sampled 13 thunderstorms found that the average speed at which they traveled across a certain state was 15 miles per hour. The standard deviation of the sample was 1.7 miles per hour. Find the 99% confidence interval of the mean. If the meteorologist wants to issue a warning so that people in the area have the maximum time to prepare and protect themselves, which figure would she likely use