A simple random sample from a population with a normal distr

A simple random sample from a population with a normal distribution of 108 body temperatures has x = 98.90 F and s - 0.64 degree F. Construct a 90% confidence interval estimate of the standard deviation of body temperature of all healthy humans. Is it safe to conclude that the standard deviation is less than 1.30 degree F? Is it safe to conclude that the population standard deviation is less than 1.30 degree F? The conclusion is safe because 1.30 degree F is outside the confidence interval. The conclusion is safe because 1.30 degree is in the confidence interval. The conclusion is not safe because 1.30 degree is outside the confidence interval. The conclusion is not safe because 1.30 degree is in the confidence interval.

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