An automotive supplier of interior parts places several electrical wires in a harness. A

Chapter 7, Problem 7.1-15

(choose chapter or problem)

An automotive supplier of interior parts places several electrical wires in a harness. A pull test measures the force required to pull spliced wires apart. A customer requires that each wire spliced into the harness must withstand a pull force of 20 pounds. Let X equal the pull force required to pull 20 gauge wires apart. Assume that the distribution of X is \(N(\mu, \sigma^2)\). The following data give 20 observations of X:

            28.8    24.4    30.1    25.6    26.4    23.9    22.1    22.5    27.6    28.1

            20.8    27.7    24.4    25.1    24.6    26.3    28.2    22.2    26.3    24.4

(a) Find point estimates for \(\mu\) and \(\sigma\).

(b) Find a 99% one-sided confidence interval for μ that provides a lower bound for \(\mu\).