Give a confidence interval for the average processing time on the basis of the sample result?

Question

The processing time for a particular type of insurance claim is thought to be normally distributed with a standard deviation of 5 minutes. Processing times are recorded for a random sample of of 36 claims. The mean of the sample is 38 minutes. a) Give a confidence interval for the average processing time on the basis of the sample result?

b) Also, it had previously been assumed that the average processing time was 40 minutes. Based on the sample, can you reject this hypothesis (at a 5% significant level)?

c) What is the p-value associated with the hypothesis test in b)? How do you interpret the p-value?

This is a statistical question. Any help on any part of the question would be appreciated. Thanks a lot!

Answer 1

Hi friend i would ask you to refer sampling theory and distributions of the book mathew grewall a text book of higher maths

I think the answer for guestion a is 85.5 seconds.