Preliminary study the population standard deviation

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A consumer agency has retained an independent testing firm to examine a television manufacturer's claim that its 25-inch console model consumes just 110 watts of electricity. Based on a preliminary study, the population standard deviation has been estimated as 11.2 watts for these sets.In undertaking a larger study,and using a simple random sample,how many sets must be tested for the firm to be 95% confident that its sample mean does not differ from the actual population mean by more than 3.0 watts?

Reference no: EM13337932

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