The most important quality characteristic of a certain product is known to be dimension and research indicates that the dimension with 20 inches can maximize the output of the product. You have collected a large number of a random sample, and the data show that the dimension is normally distributed with mean 18 and variance 4.
(a) Obtain the expected quality loss incurred by the customer? (Use the Taguchi loss function where the loss coefficient k = 1)
(b) In order to minimize the expected quality loss, what strategy would you suggest?
(c) How do you recognize that the quality characteristic under study is of nominal-the-best type?