A study of a local high school tried to determine the mean amount of money that each student had saved. The study surveyed a random sample of 59 students in the high school and found a mean savings of 4000 dollars with a standard deviation of 1000 dollars. At the 95% confidence level, use the normal distribution/empirical rule to estimate the margin of error for the mean, rounding to the nearest whole number. (Do not write ± ).Answer:
Q. A study of a local high school tried to determine the mean amount of money that each student had saved. The study surveyed a random sample of 59 students in the high school and found a mean savings of 4000 dollars with a standard deviation of 1000 dollars. At the 95% confidence level, use the normal distribution/empirical rule to estimate the margin of error for the mean, rounding to the nearest whole number. (Do not write ± ).Answer:
Understand the problem: Understand the problem and the data given.We are given the mean savings of a sample of students ($4000), the standard deviation of the savings ($1000), and the sample size (59 students). We are asked to find the margin of error at the 95% confidence level using the normal distribution.
Identify z-score: Identify the z-score associated with the 95% confidence level.For a 95% confidence level, the z-score that corresponds to the middle 95% of the normal distribution is approximately 1.96. This value can be found in z-score tables or using statistical software.
Calculate SEM: Calculate the standard error of the mean.The standard error of the mean (SEM) is the standard deviation divided by the square root of the sample size. The formula is SEM=nSD.SEM=591000
Calculate SEM: Perform the calculation for the standard error of the mean. SEM=591000SEM≈7.681000SEM≈130.21
Calculate ME: Calculate the margin of error using the z-score and the standard error.The margin of error (ME) is the z-score multiplied by the standard error of the mean. The formula is ME=z×SEM.ME=1.96×130.21
Calculate ME: Perform the calculation for the margin of error.ME=1.96×130.21ME≈255.21
Round ME: Round the margin of error to the nearest whole number.Rounded ME ≈255
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