A study by the department of education of a certain state was trying to determine the mean SAT scores of the graduating high school seniors. The study examined the scores of a random sample of 178 graduating seniors and found the mean score to be 487 with a standard deviation of 119 . 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 by the department of education of a certain state was trying to determine the mean SAT scores of the graduating high school seniors. The study examined the scores of a random sample of 178 graduating seniors and found the mean score to be 487 with a standard deviation of 119 . 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.We have the mean μ = 487, the standard deviation σ = 119, and the sample size n = 178. For a 95% confidence level, the z-score associated with it is approximately 1.96 (from the z-table or standard normal distribution table).The formula for the margin of error E when using the z-score is:E=z×(σ/n)
Calculate Margin of Error: Calculate the margin of error using the formula.E=1.96×(178119)First, calculate the denominator:178≈13.3417Now, divide the standard deviation by the square root of the sample size:13.3417119≈8.9175Finally, multiply this result by the z-score:E=1.96×8.9175≈17.4799
Round Margin of Error: Round the margin of error to the nearest tenth. E≈17.5
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