Question: Last year, Normal, Illinois, had all car maintenance on the city's automobiles done by the city main maintenance pool. The cost was $364 per car. This year, the city fathers fired all the workers in the maintenance pool and are using Jack's Crash Shop to perform the maintenance. They would like to know, without a complete audit, whether Jack is saving them money. A random sample of 36 cars showed a mean repair cost of $330, with a standard deviation of $120. What can you tell the city fathers?