From long experience, it is known that the time it takes to do an oil change and lubrication job on a vehicle has a normal distr
ibution with a mean of 17.8 minutes and a standard deviation of 5.2 minutes. An auto service shop will give a free lube and oil change service to any customer who must wait beyond the guaranteed time to complete the work. If the shop does not want to give more than 1% of its customers a free lube and oil change service, how long should the guarantee be? Round appropriately to the minute.
Rejection of aspirin argument is more dangerous because the incorrect dosage of aspirin may cause more severe adverse reactions than the incorrect dosage of vitamin C. It would be prudent to use a lower level of significance to test the aspirin argument.
