Marilyn is a statistician who works for a company that manufactures components for sound systems. Two development teams have each come up with a new method for producing one of the components, and management is to decide which one to adopt based on which produces components that last longer. Marilyn is given the data for both and is asked to make a recommendation about which one should be used. She computes 95% confidence intervals for the mean lifetime using each method and finds an interval from 96 hours to 104 hours, centered on 100 hours for one of them, and an interval from 92 hours to 112 hours, centered on 102 for the second one. What should she do? Should she make a clear recommendation? Explain.
Use the following scenario for Exercises 7 to 11: Based on the information in Case Study 26.1, describe the extent to which each of the following conditions for reducing the experimenter effect (listed in Section 26.2) was met. If you cannot tell from the description of the experiment, then explain what additional information you would need.