CONCEPT CHECK What is the minimum sample size necessary to estimate the mean number of hours adults sleep each night within a 0.03 margin of error at a confidence level of 85%? Assume a population standard deviation of 1.9 hours. [Note that the critical z-score value for an 85% confidence level is 1.44.] Answer
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We are given the following information: - Margin of error (E) = 0.03 hours - Confidence level = 85% - Population standard deviation ($\sigma$) = 1.9 hours - Critical z-score ($z_{\alpha/2}$) for an 85% confidence level = 1.44 The formula for the minimum sample Show more…
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