Answer Happy

[15 points] 3. A transport company tests the average running time for a bus on a particular route. Assume that the running times are normally distributed. Three buses are randomly observed and their running times are recorded as follows: 2. 4, and 6 hours. (a) Show that the Sample Standard Deviation is s = 2. (b) Find the one-sided lower 90% confidence bound for , the average running time. [You don't need to do the calculations, but you'll need this number in part (c).] (c) Suppose the company claims that the average running time is u = 3. Using your answer for part (b), can we claim that > 3 with 90% confidence? 1.886 is approximately 1. Hint: √3 is approximately 1.7, and so