1. Maher Saddles, Inc., produces bicycle seats. Among the many seats produced is one for the high-end mountain bicycle market. Maher's operation manager has recently made a change in the production process for this high-end seat and is scheduled to report on measures associated with the new process to become stable, he took a random sample of 25 assembly times and found a standard deviation of 47 seconds. He recognizes this is only a point estimate of the variation in completion times and so wants to report both a 90% and a 95% confidence interval estimate for the population variance.
2. Belden Inc. (NYSE: BWC) and Cable Design Technologies Corp. (NYSE: CDT) merged on Thursday, July 15, 2004. The new company, Belden CDT Inc., is one of the largest U.S.- based manufacturers of high-speed electronic cables and focuses on products for the specialty electronics and data networking markets, including connectivity. One of its products is a fiber-optic cable (TrayOptic). It is designed to have an overall diameter o inch. A standard deviation greater than 0.05 inch would be unacceptable. A sample of size 20 was taken from the production line and yielded a standard deviation of 0.070.
- Determine if the standard deviation does not meet specification using a significance level of 0.01.
- Describe a type II error in the context of this exercise.