1. Distinguish between the use of the mean, median, and mode in quality control applications. When do you prefer to use the trimmed mean?
2. State the null and alternative hypotheses in the following situations by defining the parameters used. Also, state any assumptions that you need to make to conduct the test:
(a) The Postal Service wishes to prove that the mean delivery time for packages is less than 5 days.
(b) A financial institution believes that it has an average loan processing time of less than 10 days.
(c) A marketing firm believes that the average contract for a customer exceeds $50,000.
(d) A Web-order company wishes to test if it has improved its efficiency of operations by reducing its average response time.
(e) A manufacturer of consumer durables believes that over 70% of its customers are satisfied with the product.