Question 3 An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. Form a 95% confidence interval for the population mean of all bulbs produced by this firm if a sample of 30 bulbs has an average lifespan of 780 hours
Added by Steven A.
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- The sample size (n) is 30 bulbs. - The sample mean (x̄) is 780 hours. - We want to construct a 95% confidence interval for the population mean (μ). Show more…
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An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. If a sample of 30 bulbs has an average life of 780 hours, (1) find a 96% confidence interval for the population mean of all bulbs produced by this firm. (2) find a 95% prediction interval for the life of the next bulb produced by this firm.
Madhur L.
1 . [T: 9.2] (15 pts) An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. If a sample of 30 bulbs has an average life of 780 hours, find a 96% confidence interval for the population mean of all bulbs produced by this firm.
Sri K.
3) a) An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. If a sample of 30 bulbs has an average life of 780 hours, find a 96% confidence interval for the population mean of all bulbs produced by this firm. b) How large a sample is needed if we wish to be 96% confident that our sample mean will be within 10 hours of the true mean?
Jason G.
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