Assume that you want to construct a​ 95% confidence interval estimate of a population mean. Find an estimate of the sample size needed to obtain the specified margin of error for the​ 95% confidence interval. The sample standard deviation is given.   Margin of​ error, E=4.8 ​minutes; sample standard​ deviation, s=59.2 minutes The required sample size is

You measure 32 randomly selected textbooks' weights, and find they have a mean weight of 57 ounces. Assume the population standard deviation is 2.4 ounces. Based on this, construct a 99% confidence interval for the true population mean textbook weight.Give your answers as decimals, to two places _______< μμ < _______

(assume that all variables are approximately normally distributed) Weights of Elephants: A sample of 8 adult elephants had an average weight of 12,300 pounds. The standard deviation for the sample was 22 pounds. Find the 95% confidence interval of the population mean for the weights of adult elephants. (using T distribution)

You work for a soft-drink company in the quality control division.  You are interested in the standard deviation of one of your production lines as a measure of consistency. The product is intended to have a mean of 12 ounces, and your team would like the standard deviation to be as low as possible.  You gather a random sample of 18 containers.  Estimate the population standard deviation at a 98% level of confidence.   11.88 12.03 12.04 12.1 11.97 11.89 12.05 12.07 11.96 11.87 11.9 12 12.13 12.06 11.98 11.84 12.09 12.1   (Data checksum: 215.96) Note: Keep as many decimals as  possible while making these calculations. If possible, keep all answers exact by storing answers as variables on your calculator or computer. a)  Find the sample standard deviation:   b)  Find the lower and upper �2  critical values at 98% confidence:Lower:     Upper:  c)  Report your confidence interval for �:  (  ,  ) (check image)

You work for a soft-drink company in the quality control division.  You are interested in the standard deviation of one of your production lines as a measure of consistency. The product is intended to have a mean of 12 ounces, and your team would like the standard deviation to be as low as possible.  You gather a random sample of 17 containers.  Estimate the population standard deviation at a 80% level of confidence.   11.74 12.24 11.99 12.07 12.13 11.81 12.15 12.06 11.99 12.05 12.04 12.08 11.97 12.03 11.9 12.15 12.02     (Data checksum: 204.42) Note: Keep as many decimals as  possible while making these calculations. If possible, keep all answers exact by storing answers as variables on your calculator or computer. a)  Find the sample standard deviation:   b)  Find the lower and upper χ2χ2  critical values at 80% confidence:Lower:     Upper:  c)  Report your confidence interval for σσ:  (  ,  )

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Which combination of factors will produce the smallest value for the standard error?​ ​A large sample and a large standard deviation ​A small sample and a large standard deviation ​A large sample and a small standard deviation ​A small sample and a small standard deviation