need help with with question, I read the review notes from class and don't understand. What would the answers even look like?

Here are the questions.

The expense of moving the warehouse of a UPS outlet is justified only if the mean travel distance of the delivery trucks for all shipments from this location will be less than 212 miles. In a random sample of travel distances for 105 shipments from the proposed new location, the mean travel distance was 207 miles and the standard deviation of travel distances for ALL shipments from this location is 43 miles.

A. Construct and interpret a 95% confidence interval for the mean travel distance for all shipments from the new location.

B. Determine whether the procedure used in part A is valid. Your solution should describe validity using full sentences and in the context of the problem.

C. Based upon your interval in part A, can you conclude that the mean travel distance for all shipments from the new location is less than 212 miles? Justify your conclusion.

D. Determine the number of shipments that should be selected to estimate the mean travel distance for all shipments from the new location with 95% confidence and a margin of error of 5 miles. For this problem, use the critical value associated with 95% confidence: zc = 1.96.