Question 137429
If you have a standard deviation of 86 pounds, a random sample of 90 and a mean breaking strength of 1850 pounds, find a 90% confidence interval for the true mean .
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The sample mean, x-bar, = 1850
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Comment: I'm using z=1.645 as the critical value for 90%
You might want to use a t-value if you have one.
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Margin of error = E=1.645*[86/sqrt(90)] = 14.9122
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90% CI: (1850-14.9122 < u < 1850+14.9122)
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Cheers,
Stan H.