A study was commissioned to find the mean weight of the residents in certain town. The study examined a random sample of 33 residents and found the mean weight to be 166 pounds with a standard deviation of 26 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 33 residents and found the mean weight to be 166 pounds with a standard deviation of 26 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 values and formula: Identify the values given in the problem and the formula to calculate the margin of error.We are given:- Sample mean (xˉ) = 166 pounds- Standard deviation (σ) = 26 pounds- Sample size (n) = 33 residents- Confidence level = 95%The formula for the margin of error (E) when using the normal distribution is:E=Z×(σ/n)Where Z is the Z-score corresponding to the desired confidence level. For a 95% confidence level, the Z-score is approximately 1661.
Calculate margin of error: Calculate the margin of error using the formula.First, calculate the standard error σ/n:Standard error = σ/n=26/33≈26/5.7446≈4.526Now, calculate the margin of error (E):E = Z * σ/n = 1.96 * 4.526 \approx 8.87096Round the margin of error to the nearest tenth:E \approx 8.9 pounds
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