A study was commissioned to find the mean weight of the residents in certain town. The study examined a random sample of 45 residents and found the mean weight to be 191 pounds with a standard deviation of 28 pounds. At the 95% confidence level, use the normal distribution/empirical rule to estimate the margin of error for the mean, rounding to the nearest tenth. (Do not write ± ).Answer:
Q. A study was commissioned to find the mean weight of the residents in certain town. The study examined a random sample of 45 residents and found the mean weight to be 191 pounds with a standard deviation of 28 pounds. At the 95% confidence level, use the normal distribution/empirical rule to estimate the margin of error for the mean, rounding to the nearest tenth. (Do not write ± ).Answer:
Identify given information: Identify the given information and the formula to calculate the margin of error at the 95% confidence level using the normal distribution.Given:- Sample mean (xˉ) = 191 pounds- Standard deviation (σ) = 28 pounds- Sample size (n) = 45 residents- Confidence level = 95%The formula for the margin of error (E) when using the normal distribution is:E=Z×(σ/n)Where xˉ0 is the Z-score corresponding to the desired confidence level. For a 95% confidence level, the Z-score is approximately xˉ2.
Calculate margin of error: Calculate the margin of error using the formula.E=1.96×(4528)First, calculate the standard error (nσ):Standard error = 4528Standard error ≈6.708228Standard error ≈4.1725Now, calculate the margin of error:E=1.96×4.1725E≈1.96×4.2 (rounded to one decimal place for intermediate calculation)E≈8.2Round the margin of error to the nearest tenth:E≈8.2
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