Suppose that a population of brakes supplied has a mean stoppingdistance, when the brake is applied fully to a vehicle traveling at75 mph is 268 feet. Population standard deviation is 20 feet.Suppose that you take a sample of n brakes to test and if theaverage stopping distance is less than or equal to a criticalvalue, you accept the lot. If it is more than the critical value,you reject the lot. You want an alpha of 0.03. Further, we want toreject lots with a population mean stopping distance of 282 ft., wewant to reject with a probability of 0.9. (Note that it is onesided, since we would not get worried if the vehicle stops at adistance shorter than the average time.)
- Draw a diagram and mark the two distributions, alpha, beta andCV.
- What is the correct sample size that can achieve this?
- What is the critical value?
