If a sample of 50 tires of a certain kind has a mean life
Chapter 25, Problem 25.4(choose chapter or problem)
If a sample of 50 tires of a certain kind has a mean life of 32 000 mi and a standard deviation of 4000 mi. can the manufacturer claim that the true mean life of such tires is greater than 30000 mi? Set up and test a corresponding hypothesis at a 5% level, assuming normality.
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