Two machines are used for filling plastic bottles with a net volume of 16.0 ounces. The filling processes can be assumed to be normal, with standard deviations of σ1 = 0.015 and σ2 = 0.018. The quality engineering department suspects that both machines fill to the same net volume, whether or not this volume is 16.0 ounces. An experiment is performed by taking a random sample from the output of each machine.
(a) State the hypotheses that should be tested in this experiment.
(b) Test these hypotheses using α = 0.05. What are your conclusions?
(c) Find the P-value for this test.
(d) Find a 95 percent confidence interval on the difference in mean fill volume for the two machines.