Problem Description: Critical comparison of opposing claims, analytical thinking, and problem-solving
The amount of shaft wear (.0001 in.) after a fixed mileage was determined for each of n = 8 internal combustion engines having copper lead as a bearing material, resulting in and s = 1.25. Assuming that the distribution of shaft wear is normal with mean μ, use the appropriate test at level .05 to test H0 : μ = 3.50 versus Hα : μ> 3.50. Please state any assumption you have made if necessary.
Shaft wear in excess of 3.50 could lead to catastrophic failures in extreme weather conditions. Engineers for the manufacturer of the shafts claim that the shaft wear is within acceptable limits. Lawyers representing a class action legal suit filed against the company feel that recent deaths due to catastrophic vehicle failures for engines with this shaft are due to faulty bearings.
- Conduct the appropriate hypothesis test. Whose claim would you support?
- Be sure to present the logic of your statistical approach clearly and completely to convince the Judge and jury of your position.
- Write your response as if you were presenting evidence as an unbiased expert witness.
Audience: As the expert witness for this case, your primary audience is the jury who will be reviewing the case documents. NOTE: this is a different primary audience than your reading discusses. This audience is assumed not to have the specific technical knowledge of the field the witness is explaining. The expert witness must persuade the audience of their expertise and their presentation of the case is the most credible assessment of the facts possible.
Officers of the court, legal advisories, and opposing expert witnesses are important secondary audiences, making it necessary to address any ideas that would counter your case and present why they do not disqualify your case.