The useful lifetime of Everlasts 15 volt battery is a normal

The useful lifetime of Everlast\'s 1.5 volt battery is a normally distributed random variable with mean 40 hours and variance 16 hours. A new chemical composition is introduced to make the production of the batteries more effecient. The company wants to see if the useful life of the battery has been affected (increased or decreased) by the new process. A sample of 100 batteries has been selected for analysis. a) What hypotheses should be tested? b)Suppose the new process is to be rejected is X(bar) >= 41.03 or X(bar) <= 38.97. What is the probablilty that the new process is rejected when it does not need to be? c) Using the same rejection region in part (b), what is the probability that the new process is judged not to affect the lifetime when, in fact, mu=39?

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