A Rechargeable Flashlight Is Advertised to Last Up to 2

Short Answer

A rechargeable flashlight is advertised to last up to 2 1/2 hours per charge and to recharge overnight.A test was conducted which measured the time a light lasted before needing a recharge.A random sample of 12 lights has a mean recharge time of 2.24 hours and a standard deviation of 1.05 hours.Assuming the population for recharge time is normally distributed,what is the 99% confidence interval estimate for the population mean?
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