In a report on why e-shoppers abandon their online sale transactions, a study found that "pages took me too much time to load" and "site was too confusing to me so that I couldn't find the product" were the two main complaints heard most often. Based on 40 customers' responses, the average time to complete online order was 4.3 minutes and the standard deviation was 2.6 minutes.

(a) Construct an 90% confidence interval forthe average completion time for an online order.

(b) Construct a 95% confidence interval based on a sample of size 25.

Please include the steps. Thank you!