ConfidenceIntervalPracticeSolutions

# ConfidenceIntervalPracticeSolutions - and yielded an...

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Construct 95% and 99% confidence intervals (CI) for each of the following scenarios. 1. Suppose we wish to construct an confidence interval for µ , the mean height of the population of men on a large Midwestern campus, and know that average height among men on that campus is 69 inches with a standard deviation of 3.22. Say that a sample of 10 men are taken yielding a mean of 68. Construct 95% and 99% confidence intervals for the true population mean based on the sample mean. 95% CI: 68 + 1.96(3.22/sqrt(10)) 99% CI: 68 + 2.58(3.22/sqrt(10)) 95% CI: 66 to 70 99% CI: 65.37 to 70.63 2. A sample survey of 180 people was conducted to estimate the fast-food market in a large city. The survey recorded the number of fast-food meals eaten by each person in the previous week
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Unformatted text preview: and yielded an average of .82 and a standard deviation of .48. 95% CI: .82 + 1.96(.48/sqrt(179)) 99% CI: .82 + 2.58(.48/sqrt(179)) 95% CI: .742 to .898 99% CI: .72 to .92 3. From a large class, a random sample of 4 grades were drawn yielding a mean of 74 and a standard deviation of 11.5. 95% CI: 74 + 3.182(11.5/sqrt(3)) 99% CI: 74 + 5.841(11.5/sqrt(3)) 95% CI: 52.8 to 95.2 99% CI: 33.6 to 112.8 4. A random sample of 40 cars were clocked as they passed by a checkpoint, and he average speed was 67 miles per hour with a standard deviation of 4 miles per hour. 95% CI: 67 + 2.021(4/sqrt(39)) 99% CI: 67 + 2.58(4/sqrt(39)) 95% CI: 65.69 to 68.31 99% CI: 65.3 to 68.7...
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