The tensile strength of a fiber used in manufacturing cloth isof interest to the purchaser. Previous experience indicates thatthe standard deviation of tensile strength is 2 psi. A randomsample of eight fiber specimens is selected, and the averagetensile strength is found to be 127 psi. USING MINITAB(please show all work)
(a) Test the hypothesis that the mean tensile strength equals125 psi versus the alternative that the mean exceeds 125 psi. Use a= 0.05.
(b) What is the P-value for this test?
(c) Discuss why a one-sided alternative was chosen in part(a).
(d) Construct a 95% lower confidence interval on the meantensile strength.