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 98 graduating seniors and found the mean score to be 492 with a standard deviation of 117 . 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 98 graduating seniors and found the mean score to be 492 with a standard deviation of 117 . 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 Z-score: To calculate the margin of error at the 95% confidence level using the normal distribution, we need to use the formula for the margin of error (ME) which is:ME = Z×(σ/n)where Z is the Z-score corresponding to the desired confidence level, σ is the standard deviation, and n is the sample size.
Calculate Margin of Error Formula: First, we need to find the Z-score that corresponds to the 95% confidence level. For a 95% confidence level in a normal distribution, the Z-score is approximately 1.96. This value can be found in Z-score tables or using a standard normal distribution calculator.
Plug in Values: Next, we plug in the values we have into the margin of error formula:σ=117 (standard deviation)n=98 (sample size)Z=1.96 (Z-score for 95% confidence)ME=1.96×(117/98)
Calculate Margin of Error: Now we calculate the margin of error:ME = 1.96×(98117)ME = 1.96×(9.8995117) (rounded 98 to four decimal places)ME = 1.96×11.8182 (rounded 9.8995117 to four decimal places)ME = 23.1645 (rounded to four decimal places)
Round Margin of Error: Finally, we round the margin of error to the nearest tenth: ME≈23.2
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