Exercise 13 of Chapter 1 presented a sample of n 153

Chapter 7, Problem 7.40

(choose chapter or problem)

Exercise 13 of Chapter 1 presented a sample of n 153 observations on ultimate tensile strength, and Exercise 17 of the previous section gave summary quantities and requested a large-sample confidence interval. Because the sample size is large, no assumptions about the population distribution are required for the validity of the CI. a. Is any assumption about the tensile strength distribution required prior to calculating a lower prediction bound for the tensile strength of the next specimen selected using the method described in this section? Explain. b. Use a statistical software package to investigate the plausibility of a normal population distribution. c. Calculate a lower prediction bound with a prediction level of 95% for the ultimate tensile strength of the next specimen selected.