A professor at a university wants to estimate the average number of hours of sleep students get during test week. The professor wants to find a sample mean that is within 1.89 hours of the true average for all college students at the university with 99% confidence. If the professor knows the standard deviation of the sleep times for all college students is 6.583, what sample size will need to be taken? 1) 81 2) 91 3) 80 4) We do not have enough information to answer this question since we were not given the sample mean. 5) 86
Added by Christopher M.
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E.) using the formula M.E. = (critical value) * (population standard deviation) / sqrt(n). Given that the critical value at 99% confidence is approximately 2.58, the population standard deviation is 6.583, and the margin of error is 1.89, we have: 1.89 = 2.58 * Show more…
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