...sample of 49 pens is tested, and? A certain type of pen is claimed to operate for a mean of 190 hours. A random sample of 49 pens is tested, and the mean operating time is found to be 188 hours with a standard deviation of 6 hours. Construct a 95% confidence interval for the true mean operating time of this type of pen. Does the company’s claim seem justified?
A certain type of pen is claimed to operate for a mean of 190 hours. A random...
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