Question 5.10: Refer to Example 5.4. Find both a 95% lower confidence bound......

ISE Principles of Statistics for Engineers and Scientists [987713]

Refer to Example 5.4. Find both a 95% lower confidence bound and a 99% upper confidence bound for the mean fatigue strength.

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The sample mean and standard deviation are $\overline{X} = 408.20$ and s = 72.88, respectively. The sample size is n = 70. We estimate $\sigma_{\overline{X}} ≈ 8.7108$ . The 95% lower confidence bound is $\overline{X}\ −\ 1.645 \sigma_{\overline{X}} = 393.87$ , and the 99% upper confidence bound is $\overline{X} + 2.33 \sigma_{\overline{X}} = 428.50$ .

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