confidence interval for a mean: A manufacturer claims that the average lifespan of its light bulbs is 1000hours. A random sample of 50nulbs is tested and the sample mean in 980 hours with a standard deviation of 30hours. calculate a 95% confidence interval for the true mean lifespan of the bulbs.
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Step 1: Identify the given information We are given the following information: - Sample size (n) = 50 - Sample mean (x̄) = 980 hours - Sample standard deviation (s) = 30 hours - Confidence level = 95% Show more…
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