Discuss the below:
Q1. What is a control chart? What are the grand mean, the UCL and the LCL of a control chart for the mean? Why do you suppose -3/+3 standard errors are used in control charts and not two standard errors or even one standard error? Explain.
Q2. A significance test is used to prevent a machine from underfilling or overfilling quart bottles. On the basis of a sample, the null hypothesis is rejected and the machine is shut down for inspection. A thorough examination reveals there is nothing wrong with the filling machine. From a statistical standpoint, was there a "type" error made? If yes, which type? Explain.